Wolf Creek

000
FXUS65 KPUB 312331
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
531 PM MDT Sat Oct 31 2026

.KEY MESSAGES...

- High impact heavy precipitation/flooding event still on track
  for the eastern San Juans and portions of the San Luis Valley
  Sun/Mon, with flooding along the mainstem Rio Grande possible
  Mon-Wed. 

- Showers and isolated thunderstorms elsewhere over the
  mountains/valleys (snow higher peaks) Sun/Mon, with windy
  conditions and showers over the plains on Mon/Mon evening. 

- Drier Tue, then a weak weather system will bring back a chance
  for showers to the region Wed/Thu.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 100 PM MDT Sat Oct 31 2026

Quiet today across the region as initial s/w trough has moved
through, though satellite images show large area of Pacific 
moisture poised to move onshore tonight as West Coast upper
trough begins to move eastward. Precip will reach the 
Continental Divide after midnight as sw flow deepens, with 
steadier/heavier activity developing by sunrise on Sun as 
upward motion increases. Could see some snow briefly mix in down
to 10k feet or so early in the morning, before snow level 
begins to climb toward 12k by midday as warm/moist Pacific air 
mass spreads in. Heavy rain then continues over the San Juans
through the day on Sun, with lighter spillover showers into the
San Luis Valley/Sangres/central mountains during the afternoon.
Forecast QPF for Wolf Creek Pass for the 12hr period of 12z Sun
through 00z Mon is over 2 inches, with 1-2 inches forecast
farther south over the headwaters of the Conejos River. This
rainfall, along with some melting of the snowpack above 10k
feet, will likely cause widespread flooding, especially along 
the Conejos River and the South Fork of the Rio Grande.  

Sunday night, first piece of energy ejects from the upper
trough, spreading at least some weakening showers and isolated 
thunderstorms eastward out of the mountains and into the plains,
while steadier/heavier precip continues along the Continental
Divide. Snow level finally begins to fall toward 10k feet around
midnight over the San Juans, then a quicker fall to below 9k
feet is forecast by 12z, as upper trough and colder air finally
move overhead. Another 1 to 2 inches of liquid is forecast from
00z Mon through 12z Mon, though a portion of this will fall as
snow as temps cool. 

Overall, previous forecast was in good shape, main changes were
to increase QPF slightly, start snow in the San Juans a few
hours later, and to decrease snow amounts given later start to
snowfall. Upgraded winter storm watch to a warning for the San
Juans, as once precip switches, could get a quick foot or more
from Wolf Creek Pass up through the higher peaks. Also added 
pops to the plains Sun night, as precip moves off the mountains,
and a few thunderstorms develop along the surface trough over 
sern CO.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 100 PM MDT Sat Oct 31 2026

On Monday, upper trough ejects eastward across CO, with precip
tapering off over the southwest mountains through the day as
flow becomes more w-nw, while showers linger elsewhere over the
remaining mountains and valleys. Strong cold front will swing 
through the plains early Mon as surface/mid level low moves 
into KS, with strong north winds and a period of showers and 
thunderstorms likely along and east of I-25 as vertical motion 
increases under the deformation band. Will have to watch for a 
burst of heavier precip (rain and snow) along the east 
slopes/Palmer Divide/Raton Mesa Mon afternoon/evening, especially
if surface winds can take on a a slightly more nely component. 
Wind gusts could get close to 60 mph on the plains as low wraps
up, and will have to monitor areas near the KS border for a 
potential wind highlight if model trends continue. Precip then 
ends Mon evening, with a dry day on Tue as upper ridge briefly 
returns to the area. 

Still some uncertainty concerning the mid/late week forecast, as
model solutions now show weak energy sliding through the Rockies
Wed/Thu, generating a few showers/mtn snow showers across the
region through the period. Not expecting heavy precip as system
will be rather moisture-starved, though some light snow
accumulations over the higher mountains look possible. Solutions
regarding the position and timing of the next major upper 
trough for late week into the weekend still vary widely, though 
an eastward shift in the trough position has been noted in the
overall model/ensemble data, which could limit impacts to srn
CO.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 530 PM MDT Sat Oct 31 2026

Mid and high level cloudiness pushing across the Four Corners and 
into the western half of the state. Main story for terminal 
sites will be development of stratus across the eastern plains, 
and incoming showers crossing the Continental Divide into the 
San Luis Valley.

KCOS: VFR through 07z, then IFR/LIFR conditions developing due to 
low stratus and patchy fog. Improving conditions after 14z.

KPUB: VFR through 07z, then IFR/LIFR conditions developing due to 
low stratus and patchy fog. Improving conditions after 19z.

KALS: VFR conditions through 10z, then showers in the vicinity. 
Starting 12z and onward, gusty southerly winds to 30 kt and MVFR 
conditions developing due to lowering cigs and -SHRA.

&&

.HYDROLOGY...
Issued at 100 PM MDT Sat Oct 31 2026

Main concern continues to be flooding along the Conejos River
and the South Fork of the Rio Grande, especially Sunday night 
into Monday morning. Models today have come in slightly wetter 
and warmer with incoming Pacific weather system, and a 
prolonged period of rain on snow looks likely in the San Juans 
well into Sunday evening. Snow level rises to above 11000 feet 
during the day Sunday, and only slowly falls to around 10000 
feet Sunday evening, then below 9000 feet by Monday Morning. QPF
over/along the Continental Divide has come up to between 3-4 
inches of liquid (some of which will be snow) which will be 
sufficient to cause flooding even without the additional 
potential runoff from melting snow. Runoff peak should be late 
Sun evening, before snow level falls and run-off starts to 
decrease early Mon morning. River stage forecasts continue to 
indicate significant flooding, with the South Fork of the Rio 
Grande at South Fork and the Conejos River at Mogote rising well
above flood stage Sunday evening, cresting overnight into early
Monday morning. These high flows will then move downstream 
Mon/Tue/Wed with flooding possible on the mainstem Rio Grande at
Del Norte/Monte Vista and Alamosa and along the Conejos River 
east of Mogote through the period. Flood watch remains in effect
for all of the San Luis Valley from late Sun night into Tue 
morning, mainly for mountain runoff, as rainfall in the Valley 
itself should be between .5 and 1.5 inches.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch from late tonight through Monday morning for 
COZ067-068.
Winter Storm Warning from 5 PM Sunday to 11 AM MDT Monday for 
COZ068.
Flood Watch from Sunday afternoon through late Tuesday night 
for COZ069>071.

&&

$$

SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...MOORE
HYDROLOGY...PETERSEN