973
FXUS65 KBOU 131944
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
144 PM MDT Tue Oct 13 2026

.KEY MESSAGES...

- Much cooler temperatures and wet conditions is still on track.

- Rain and mountain snow showers will become more numerous
  tonight, mainly west of I-25. More widespread rain and mountain
  snow still on schedule for Wednesday afternoon - Wednesday
  night, before winding down Thursday.

- Several inches (6-12") of snow expected for the mountains above
  9,000 to 10,000 feet with travel impacts late Wednesday thru
  Thursday morning. Lighter snow and at least a dusting into the
  mountain valleys and higher foothills.

- Drier and warmer again for next weekend.

&&

.DISCUSSION /Through Tuesday/...
Issued at 144 PM MDT Tue Oct 13 2026

Satellite imagery shows the upper level low diving southeast
across Nevada. The low will bottom out over northern Arizona
tonight and be centered over the Four Corners 18Z Wednesday. Water
vapor imagery and radar show an area of lift over eastern Utah
and western Colorado, with widespread showers. This area of lift
shifts eastward tonight bringing rain and mountain snow showers to
the western two-thirds of Colorado. Easterly low level flow will
continue tonight and Wednesday around the low to our southwest and
a surface high to the north. Cross sections show that the low
levels will become saturated overnight and Wednesday. This
saturated layer becomes deep enough for drizzle late tonight and
Wednesday. The upper level low tracks northeast across Colorado
Wednesday afternoon through Wednesday night bringing widespread
rain and high country snow. The best snowfall for the mountains
comes later Wednesday and Wednesday night when flow becomes a
favorable northwest direction (for orographic lift). We`ve issued
a Winter Weather Advisory for the mountains where 6 to 12 inches
of snow are expected.The snow level tonight will be 10,000 to
11,000 feet dipping below 10,000 feet over the northern mountains
towards sunrise Wednesday morning. Once the low moves over
Colorado, the snow level falls to 8,000 feet around sunset
Wednesday evening and 7,500 feet by Thursday morning. Rain and
snow linger into Thursday, especially across northern Colorado,
wrapping up during the afternoon.

Skies clear out around sunset Thursday night as a surface settles
over Colorado. This will bring the coldest night so far this
fall. Many places will see a frost or freeze Thursday night and
Friday morning. Overnight lows are on track to be in the upper 20s
to mid 30s over northeast Colorado. Typical low lying areas/cold
spots are expected to fall into the mid to lower 20s.

An upper level high will be centered over the intermountain west,
with a closed low trapped beneathit off the coast of northwest
Mexico on Friday. Cross sections show a very dry airmass,
resulting in sunny skies all day on Friday. Cool air lingers with
highs in the upper 50s to lower 60s, but light winds and sunny
skies will make it feel warmer. The upper level ridge slides east
of the region Saturday. Southwestflow aloft will prevail behind
the ridge bringing warmer air to the area. Temperatures climb
above normal with highs expected to reach upper 60s to lower 70s
across northeast Colorado.

A weak trough in the flow aloft tracks across the Central Rockies
on Sunday. It also absorbs the upper level low off the northwest
Mexico coast. Models indicate very little moisture will accompany
this trough, thus dry conditions are expected to continue Sunday.
Temperatures may take a small step back.

Mild and dry conditions are expected for Monday andTuesday as
southwest flow redevelops over the Central Rockies ahead of a
deepening trough along the west coast. This trough tracks eastward
mid to late next week bringing the next chance for rain, mountain
snow, and cooler temperatures.

&&

.AVIATION /18Z TAFS through 18Z Wednesday/...
Issued at 1204 PM MDT Tue Oct 13 2026

Satellite shows the stratus deck is slowly breaking, with one
patch of brief clearing currently working southwest toward KDEN,
with a somewhat higher deck forming behind that near 2000-3000 ft
AGL. We should see a slow but continued breaking of the deck with
additional daytime heating, with mostly VFR conditions for a few
hours late this afternoon and early evening. Then low clouds will
settle in again and overspread the TAF sites, most likely 03Z-06Z
and then lowering to IFR/LIFR with ceilings down to 500 ft or less
starting 06Z-08Z. These will hold through all day Wednesday. One
batch of showers will attempt to move across the airports 23Z-04Z,
with more widespread showers and drizzle likely affecting KBJC
after midnight. KDEN and KAPA would be more prone to the drizzle
side through 16Z since moisture is quite shallow there. Showers
will become more widespread across all TAF sites after 21Z
Wednesday, with a low (10%) chance of thunder.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from noon Wednesday to 6 AM MDT Thursday
for COZ031-033-034.

&&

$$

DISCUSSION...BM
AVIATION...20

NWS BOU Office Area Forecast Discussion