230
FXUS65 KBOU 091135
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
535 AM MDT Thu Apr 9 2026

.KEY MESSAGES...

- Scattered showers Thursday afternoon/evening. Rainfall amounts
  will be light (less than 0.10").

- A brief cool down Friday with a 20-30% chance for light rain.

- Warm and mostly dry for the weekend. Scattered showers possible
  Saturday with a few thunderstorms, mainly over the mountains and
  far northeast plains. Dry Sunday.

- A spring storm possible Tuesday/Wednesday with heavier
  precipitation amounts possible.

&&

.DISCUSSION /Through Wednesday/...
Issued at 1103 PM MDT Wed Apr 8 2026

Westerly flow aloft will be across the area on Thu as a weak
disturbance is possibly embedded in the flow.  Cross-sections show
moisture is mainly limited to the mid levels.  Sfc based capes are
under 300 j/kg.  Thus appears most activity in the aftn will be
rather high based with brief gusty winds occurring with any shower
activity.  Highs will be in the lower to mid 70`s across nern CO.

For Thu night, a cool front will move across the plains with some
increase in low level moisture behind it. With upslope flow in
the evening hours combined with the weak disturbance moving
across, there could be a better chc of showers in the evening
across the plains. Meanwhile, will likely see low clouds and some
fog overnight into Fri morning.

On Fri, the low level flow will gradually become southeast thru the
day with a Denver cyclone developing.  There will be a convergence
zone associated with this feature by aftn.  Sfc based cape near the
convergence zone will be around 500 j/kg if temps rise into the
upper 60s. Thus a few storms may develop by late aftn along this
zone. Elsewhere across the plains, it will be cool with less
instability as temps remain in the 50`s. In the mtns, there will
be a chc of showers and possibly a tstm.

For Sat, the flow aloft will be from the southwest. A disturbance
embedded in the flow may bring a good chance of showers to the
mtns. Across the plains, gusty south winds will develop as a sfc
lee trough forms. Sfc based capes will be around 500 j/kg with
possibly up to 1000 j/kg over the far northeast plains by late
aftn. Thus could see a few stronger tstms by late aftn into the
early evening hours over the far nern plains. Highs on Sat will be
warmer as readings rise back into the 70`s over nern CO.

By Sun, drier air in SW flow aloft will spread across the area which
will limit precip chances.  Highs will remain in the 70`s across the
plains.  For Mon, a storm system will move into the Great Basin with
stg SW flow aloft over the area, as sfc low pres resides over nern
CO. As a result, may see another warm and dry day across the plains.
In the mtns, moisture will increase by aftn with a chc of showers.

Looking ahead to Tue, quite a bit of uncertainty remains as to the
timing and track of the storm system over the Great Basin. The
latest GFS has it moving quickly over the area on Tue with the main
low tracking across Wyoming.  This track would favor the mtns for
precip while the plains would be mainly dry and windy.  Meanwhile,
the 12z ECMWF was slower and further south with the low as it moves
into ern ern Colorado by Tue aftn. As a result this would bring a
better chc of precip to portions of the plains. Overall, will
see varying solutions for this system over the next 3 to 4 days.

&&

.AVIATION /12Z TAFS through 12Z Friday/...
Issued at 528 AM MDT Thu Apr 9 2026

VFR through the TAF period, with gusty high-based showers the main
concern today.

Winds are light and should remain light and variable through most
of the morning, before slowly turning towards the north or
northeast this afternoon. Guidance keeps these winds relatively
weak and given the potential for multiple rounds of virga/outflow
from showers today, I expect there to be at least a few wind
shifts this afternoon into the early evening. Can`t rule out a few
gusts of ~30kt with any stronger convection that develops. It also
wouldn`t be surprising to see a weak thunderstorm or two near the
terminals if better instability manages to develop.

Some showers may linger into the evening hours, complicating the
typical turn towards drainage. A few CAMs keep a majority of the
evening SHRA north of the terminals, and any outflow would likely
lead to a north/northeast wind continuing. The most likely
scenario advertised by MOS guidance is for a slow turn to the
east/southeast, which would likely continue through most of Friday
morning.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...Hiris

NWS BOU Office Area Forecast Discussion