971
FXUS65 KPUB 171142
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
542 AM MDT Thu Sep 17 2026

.KEY MESSAGES...

- Monsoon activity continues through the weekend. Heavy rainfall and
flash flooding will be the primary concern over and near the
mountains.

- Some thunderstorm activity remains possible over the eastern
plains as well through Sunday.

- A bit drier late Saturday into Sunday, before cooler and
  possibly wetter conditions return next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 1254 AM MDT Thu Sep 17 2026

Currently, SE Colorado sits in between two larger systems; a broad
upper low moving down from the Pacific NW, and a region of high
pressure over the southeast states. Aloft, flow in our region
remains out of the southwest, with plenty of monsoon moisture
continuing to funnel into our CWA. Lingering overnight showers will
last into the morning, mainly over our western mountains. By mid-
afternoon, some passing shortwave energy, combined with lee
troughing over the plains, will initiate another round of
thunderstorms over large portions of the area. Again, most activity
will stay over/near the higher terrain, but a few thunderstorms will
move east onto the plains as well by the end of the day. Looking at
potential impacts, our main concern will be heavy rainfall, which
could result in flash flooding over the burn scars, but also across
areas that have received repeated or nonstop precipitation over the
last 24 hours. Given the persistence of showers our west, Flood
Watch over the San Juans remains in place until 12AM Friday. Showers
will continue through most of the night, retreating further west but
not fully ceasing over the San Juans as we head into Friday.
Meanwhile, temperatures for today will be similar to yesterday, with
80s to low-90s over the plains and 70s for the high valleys.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 1254 AM MDT Thu Sep 17 2026

The monsoon plume continues funneling into our area on Friday,
though the best moisture tap will shift a bit further west. Most of
the precipitation for Friday will be over the mountains, with a
continued chance for heavy rainfall and flash flooding. Meanwhile,
some afternoon showers and storms will be possible over the plains
as well, but things further east will be more isolated. The
exception to this will be the Palmer Divide, which should see some
more widespread rain thanks to a weak incoming cold front in the
evening. Post-frontal upslope will make the plains a bit more active
on Saturday, with some lingering low-level moisture and instability
through the afternoon hours. Another front will also move through
sometime Saturday evening into early Sunday, which will help keep
convection going over the area.

Meanwhile, drier air will work its way into the mountains as flow
aloft turns westerly on Sunday. The mountains will largely dry out,
leaving some isolated-scattered activity over the plains in the
afternoon hours. Meanwhile, the passing fronts will knock
temperatures down a few degrees for the weekend. By Sunday highs
will largely remain in the 70s over most of our CWA. Heading into
next week, cooler temperatures look to stick around, with the
monsoon moisture returning as an upper low moves onto the CA coast.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 541 AM MDT Thu Sep 17 2026

KCOS and KPUB: VFR conditions are expected over the next 24 hours.
Light winds at the start of this TAF period will increase slightly
this afternoon as modest mixing materializes, with gusts to 20-25
knots expected. These winds are then expected to lessen again
heading into the evening and into tomorrow morning. Showers and
storms will once again be a concern for either TAF site today, with
the most likely timing for any impacts this afternoon into early
evening. Brief periods of heavy rain, reduced visibility, gusty
outflow winds, and lightning will be the main concerns will any
thunderstorms. Otherwise, mid to high level clouds will persist
through this TAF period, with some lifting and thinning of clouds
late tonight and into tomorrow morning.

KALS: VFR conditions are expected over the next 24 hours. Light
winds at the start of this TAF period will increase slightly this
afternoon as modest mixing becomes established, with gusts to
20-25 knots expected. These winds are then expected to lessen
again heading into the evening and into tomorrow morning.
Showers and thunderstorms will again be a concern today,
especially this afternoon and evening, when confidence is
greatest in precipitation development. Brief periods of heavy
rain, reduced visibility, gusty outflow winds, and lightning
will be the main concerns will any thunderstorms. Otherwise, mid
to high level clouds will persist through this TAF period.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this evening for COZ067-068.

&&

$$

SHORT TERM...GARBEROGLIO
LONG TERM...GARBEROGLIO
AVIATION...SIMCOE