721
FXUS65 KBOU 111200
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
600 AM MDT Sun Oct 11 2026

.KEY MESSAGES...

- Another unseasonably warm and mostly dry day expected Sunday.

- Isolated to scatteredshowers (15-35% coverage) and a couple
  weak storms over themountains possible again Sunday afternoon.
  Any precipitation would be light.

- Pattern change next week, with cooler temperatures
  finallyarriving by Tuesday. Main precipitation chances hold off
  until at least late Tuesday, but uncertainty remains.

&&

.DISCUSSION /Through Saturday/...
Issued at 1134 PM MDT Sat Oct 10 2026

While a fairly active synoptic pattern continues across the CONUS,
with multiple tropical systems pulling moisture northward into the
mid-latitudes, our forecast area continues to sit just out of reach
of the greatest tropical surges for any significant precipitation
chances. Not all hope is lost though, as guidance continues to show
a pattern change headed our way by midweek, with a few inches of
snowfall on track to grace our highest elevations, and some much-needed
measurable rainfall expected for our lower elevations.

On Sunday, an upper-level low will continue it`s trek southeast out
of the Pacific Northwest, pulling the remnants of Tropical Storm
Rachel northeast into the Great Basin and portions of the
Intermountain West. Both operational and ensemble guidance remain
consistent in showing the greatest moisture largely staying west and
north of our forecast area, with only light precipitation expected
across our higher elevations. Southwesterly flow aloft will increase
throughout the day, with a 65 to 75 kt 500 mb jet expected to
straddle the UT/CO border by the early evening hours. Despite
ensembles showing PWAT values averaging around 190% of normal,
without the assist from any lower-level cold front or real upslope
component, the lee side of the Front Range and plains will miss out
on any measurable precipitation. A few hundredths can be expected
for the higher elevations, with up to .2" possible for the
highest elevations in Jackson County. At least increased cloud
coverage will allow for a few degrees of cooling for afternoon
highs across the urban corridor, where low 80s are forecast,
marking the end to any mid 80s potential for the remainder of the
period. A few showers may linger into the late night hours, mostly
for our northern mountains where temperatures are expected to
remain too warm for snowfall outside of potential for a dusting at
our highest mountain tops.

For Monday, guidance remains fairly consistent across the board,
continuing to show southwesterly flow aloft increasing as a deep
trough remains over the western CONUS, and a closed low moving into
northern Nevada by the evening hours. PWAT values are expected to
drop off significantly across the lower elevations, where ensembles
show them at 80-100% of normal, and staying around 130-150% of
normal for the mountains and Cheyenne Ridge as the majority of
Rachel`s remnants move into the Northern Rockies. Mostly dry
conditions are expected across the forecast area, with the
exception of isolated afternoon showers possible for the
mountains. Afternoon high temperatures should see a few more
degrees knocked off before a more significant cooldown is expected
on Tuesday. Meanwhile, remnants of Hurricane Simon are expected
to start moving northward through Mexico, getting funneled into
the central CONUS around a high centered over the Gulf and
aforementioned trough over the west through the week. A cold front
is expected to push south into Colorado overnight Monday that
will cool temperatures on Tuesday to near-normal values for the
northern plains, with warmer temperatures (5-10 degrees above
normal) expected for Elbert and Lincoln Counties.

Guidance continues to diverge on the evolution of the trough,
although the 18Z ensembles stay fairly consistent through about
Wednesday afternoon now. While there are still some details to
iron out, we are expecting precipitation to increase Tuesday
night, with Wednesday looking like a damp and cool day across the
forecast area, with measurable rainfall even forecast for the
lower elevations for the first time in a while. It`s hard to
remember the last time both the ECMWF and GFS ensembles had almost
every single member bringing QPF to the plains, and the 18Z
output does just this. Between around 6Z Wednesday and 6Z Friday,
we could see a few locations over the plains with around a half of
an inch of QPF, some with a little more, and some with a little
less. At this time it does look like some upslope from the surface
to around 700 mb will help enhance precipitation totals for the
foothills of Larimer County and the Cheyenne Ridge, but we will
have to see if we can get some better agreement in guidance in the
next few days to dial the forecast in some more. As for our
higher elevations, snowfall is expected, mainly above 10,000 feet,
that will likely bring our best totals of the season thus far,
with at least a few inches expected for our northern mountains. As
for temperatures, cooler temperatures are expected to stick
around through the week, with another cold front expected sometime
Thursday night into Friday, before a slight warmup looks on track
for next weekend.

&&

.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 558 AM MDT Sun Oct 11 2026

Current winds over the Denver metro are light (

NWS BOU Office Area Forecast Discussion