429
FXUS65 KPUB 152335
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
535 PM MDT Tue Sep 15 2026

.KEY MESSAGES...

- Multiple waves of showers and thunderstorms expected Wednesday
  through Friday with a heavy rainfall/flash flood risk for the
  mountains, especially the eastern San Juans.

- Moisture plume shifts eastward slightly late Friday into
  Saturday, bringing a better chance for showers/storms to the
  eastern mountains/I-25 corridor and southeast plains.

- Potentially drier Sunday/Monday, though model solutions for
  this period have bounced between dry/wet the past few runs.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 159 PM MDT Tue Sep 15 2026

Currently, cold front has moved through all the southeast
plains, with gusty north winds turning se and diminishing over
all but the far east as of 1 pm. Starting to see low clouds over
the eastern plains breaking up early this afternoon, though
stream of mid/upper level cloud cover over much of the area will
continue to keep temps cool through the remainder of the day.
Precip so far has been rather sparse, with just a few weak -tsra
developing over the mountains as of 130 pm, while a few storms
over northern NM were moving northeast toward the srn Sangres.
CAMs suggest best coverage of storms through the afternoon into
the evening will be over the Sangres, with a few storms back
along the Continental Divide as well. A few weakening
showers/storms could drift into the I-25 corridor this evening,
though precip amounts away from the mountains look light. Area
of storms over nern NM later tonight may then push northward
into the far southeast plains after midnight, while at least
isolated activity percolates along the Continental Divide for
much of the night. Not much of strong/severe threat with any
storms this afternoon/tonight, though some brief heavy rainfall
may occur, especially over the ern San Juans where moisture
continues to deepen.

On Wednesday, upper ridge builds slightly, with mid level flow
becoming more sly through the day. This will lead to warmer
temperatures and a substantial upturn in shower/thunderstorm
chances across srn CO, as deeper moisture over AZ/NM is brought
northward into the region. Areas along the Continental Divide
look most favored for heavy rainfall, especially the eastern San
Juan Mountains, where a flash flood watch is in effect. Storm
coverage decreases slightly farther east, though still expect at
least scattered storms along I-25 and across the plains, as
weak surface trough roughly from Trinidad to Eads may enhance
storms away from the higher terrain. CAMs occasionally show a
couple of stronger storms near the Aspen Acres Burn Scar Wed
afternoon, though still not enough confidence in storm
location/intensity for a flash flood watch here. Max temps will
climb 5-10 degf over the plains, while readings over the
mountains only nudge up a degree or two.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 159 PM MDT Tue Sep 15 2026

Moisture plume continues overhead Wednesday night, with rain
chances continuing well into the night over much of the area.
Forcing for heavy rain continues look strongest over the eastern
San Juans, where flash flood watch will continue. Thursday
looks like a repeat of Wednesday, as sly mid-level flow brings
both moisture and weak s/w energy northward into the area. Flash
flood watch will continue for the ern San Juans, where models
suggest storm totals of over 2 inches by Thu evening. Won`t
issue any further flash flood watches at this point, but will
have to closely monitor both the Willow/Aspen Acres scars for
heavy rainfall.

Pacific NW upper trough then moves eastward through the nrn
Rockies Fri/Sat, potentially dragging the main mid-level
moisture plume slightly eastward into the eastern mountains and
plains by Sat afternoon. Still expect another day of widespread
showers/storms on Fri, then perhaps a better focus for storms
over the eastern mountains and plains on Sat, with moist plume
overhead and weak cold front in the vicinity by Sat evening.
Forecast gets less clear Sun/Mon, as older NBM keeps convective
threat going both days, while latest 12z deterministic models
(GFS/ECMWF) both show increasing wly flow and fairly strong
drying over the region both days. Forecast currently reflects
the wetter NBM, but potential is growing that we may at least
see a decrease in precip chances as we get into early next week.
Temps Thu/Fri/Sat look mainly seasonal (70s/80s) then slightly
cooler Sun/Mon as upper trough and cold front swing through.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 522 PM MDT Tue Sep 15 2026

KALS...showers and thunderstorms will be possible at the
terminal through 02Z with gusty winds near 35 kts accompanying
them. CIGS near 4 kft will be possible overnight with light
winds less than 10 kts. Southerly winds increase on Wednesday,
with another round of afternoon showers and thunderstorms
expected across the San Luis Valley after 21z.

KCOS...VFR conditions this evening, with southeast winds
overnight. This will likely lead to stratus development near 2
kft late tonight into Wednesday morning. Southeasterly winds
continue through Wednesday. Showers and thunderstorms look to
hold off until after 00Z/Thurs.

KPUB...east to southeasterly winds will prevail overnight and
weaken this evening. The southeasterly winds will likely lead to
low stratus near 2 kft late tonight into Wednesday morning.
Southeasterly flow increased during the afternoon. Model
guidance suggests showers and thunderstorms moving to near KPUB
during the afternoon.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch from Wednesday afternoon through Thursday evening
for COZ067-068.

&&

$$

SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...MOZLEY