North Lone Pine Trail Colorado Weather Forecast Discussion

241
FXUS65 KBOU 120037
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
637 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 /00Z TAFS through 00Z Monday/...
Issued at 540 PM MDT Sat Oct 11 2025
VFR conditions expected through the TAF period. Much drier air has
moved in behind this afternoon`s showers. Winds have returned to
light and variable where they are expected to remain before
turning to a persistent southerly component for the overnight
hours (between 2-3Z). A cold front is expected to slide south
across the TAF sites tomorrow morning. Expecting winds to
become gusty (20-25 kt gusts) and shift to a northerly component
as it passes. Models are typically a little slow with cold front
timing, but expecting the northerly winds to begin at KDEN between
13-15Z before pushing south into KAPA between 15-16Z. Winds at
KBJC will be a little trickier to nail down, as cross-sections
show between 35-45 kts of cross-barrier flow creating mountain
wave enhancement ahead of the cold front late tonight/early
tomorrow morning. Hi-res guidance shows winds make a turn to the
southeast as the mountain wave first develops at KBJC (around 7Z).
If the southeast turn doesn`t play out, winds are expected to
gradually turn more westerly through the early morning gusting to
25 kts as winds make their way down the eastern slopes of the
Front Range.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...MAI
AVIATION...999

NWS BOU Office Area Forecast Discussion