689
FXUS65 KBOU 112031
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
231 PM MDT Sat Oct 11 2025

.KEY MESSAGES...

- Scattered showers and isolated thunderstorms ending this evening.

- Windy with a quick shot of snow over the northern mountains
  early Sunday.

- Precipitation chances return late Monday across the mountains
  and plains.

- Above normal temperatures expected mid-week.

&&

.DISCUSSION /Through Saturday/...
Issued at 220 PM MDT Sat Oct 11 2025

Current radar shows scattered light showers over the mountains and
plains, which will end this evening as an upper level shortwave
reaches Colorado. With tropical moisture being advected into our
region, snow levels will stay above 12,000 feet. We have been slow
to warm up across the western/northwestern plains today as a
surface lee trough has formed, keeping the warmer southeast winds
to the east of the low. Current observations show temperatures in
the mid 60s closer to the foothills, while the farther eastern
plains have already reached mid to high 70s. With the expected
cloud cover through this evening, temperatures most likely will
stay in the 60s for the majority of the plains.

There will be a lull in precipitation across the mountains and
plains tonight. Just before sunrise, the upper level shortwave
will travel across Wyoming and advect cold air into our region,
along with providing enough forcing for precipitation across the
higher terrain. 700-mb temperatures should get down to -2 to -4
dg C, which would support snow levels above 8500 feet. Expect 1-4"
along the western slopes of the Park Range and Front Range
mountains by early Sunday afternoon. In addition, with cross-
barrier flow of 30-40 kts. winds could gusts up to 50 mph at the
highest peaks, which will make blowing snow likely through early
Sunday afternoon.

For the plains, downsloping winds should keep conditions dry on
Sunday. A well-defined cold front will arrive sometime in the
morning, bringing wind gusts up to 45 mph in the northern plains.
With minimum relative humidity values between 20-25%, elevated
fire weather conditions are possible in the north and northeastern
plains.

Monday will be cooler behind the cold front, with max
temperatures in the low 60s across the plains and 40s-50s in the
higher terrain. With south/southwest flow aloft, warm air
advection will aid in light showers across the forecast area. As
of right now, NBM looks sufficient in the spatial extent of PoPs,
with best chances of precipitation across the mountains and
eastern plains.

Around mid-week, we will continue to be under southwest flow
aloft due to an upper level low forming over California and a
ridge building over the southern United States. At the surface,
southerly winds will bring warmer and drier conditions, with
temperatures expected to be 10-15 degrees above seasonal normals.

By the end of the week, the upper level trough will travel northeast
from California and track into Wyoming. However, there is still
model variability in terms of track, evolution, and intensity of the
low. Some ensemble solutions favor a piece of energy breaking from
the main trough and traversing Colorado, which would bring
precipitation chances back to the mountains and plains by Thursday.
Will continue to monitor the situation.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1133 AM MDT Sat Oct 11 2025

VFR conditions through the TAF period. The boundary associated
with the DCVZ has set up SE of DEN, and thus the stronger S/SE
will most likely not make it to the terminal. Expect light VRB
winds for the next couple of hours. Light rain showers are
likely between 19Z and 23Z, with VRB wind gusts up to 25 kts.
Ceilings could drop down to 6000 ft.

Behind the showers, northwesterly winds should prevail before
turning drainage overnight. Tomorrow, a well defined cold front
will arrive as early as 14Z, with northerly wind gusts up to 25
kts.

&&

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

&&

$$

DISCUSSION...MAI
AVIATION...MAI