454
FXUS65 KPUB 172038
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
238 PM MDT Thu Sep 17 2026

.KEY MESSAGES...

- One more day of widespread showers and thunderstorms over the
  mountains on Friday, with pockets of heavy rainfall again
  possible.

- Thunderstorm activity may then increase over the plains late
  Saturday into Sunday as a cold front moves through the area.

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

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 135 PM MDT Thu Sep 17 2026

Currently, initial s/w trough which brought widespread showers
to many locations overnight/early this morning was lifting into
nrn CO, with a pronounced downturn in precip across the area
early this afternoon. Still some light to briefly moderate rain
in spots along the Continental Divide as of 130 pm, but overall,
next round of thunderstorm development has been slowed by
clouds and weak subsidence behind the departing wave. Most
models suggest storm redevelopment after 3 pm, with ern San
Juans/srn San Luis Valley and the srn Sangres looking most
favored for stronger activity as convection moves northward out
of NM. Peak storm coverage according to many CAMs may not come
until 6-7 pm, with even some weakening activity drifting into
the I-25 corridor possible. Will keep flash flood watch up until
midnight for the sw mountains, where models suggest heavier
rain is possible through at least sunset. Overnight, convection
diminishes greatly after midnight, with only some lingering
showers along the Continental Divide into Fri morning. On Fri,
one more day of widespread mountain showers/thunderstorms
expected, as Pacific NW upper low begins it`s eastward trek into
the Rockies. Best storm coverage again along the Continental
Divide, with mainly isolated storms from I-25 eastward. Max
temps will nudge upward, with some low/mid 90s over the
southeast plains.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 135 PM MDT Thu Sep 17 2026

On Saturday, upper low moves into wrn WY, with strengthening wly
flow over CO bringing in a drier air mass, especially over the
mountains. While we won`t shut off convection completely as
upper trough extending south from the WY low will provide some
modest upward motion, storm coverage/strength will be lower
than the past few days over most of the higher terrain Sat
afternoon and evening. For the eastern mountains and southeast
plains, forecast hinges on how fast cold front arrives and how
much low level instability develops behind it by late day. Most
model forecasts have boundary near the Arkansas River by late
Sat afternoon, then progressing south toward the NM border
through the evening. Combination of best upper forcing and
greatest low level instability are currently forecast over nern
CO Sat afternoon/evening, though instability/shear over sern CO
look more than sufficient for storms to build s-sw into the
area, especially mid to late evening. Nudged up NBM pops a bit
Sat afternoon/evening to account for this scenario, though
overall blended guidance didn`t look too bad for this period.

Strong wly flow aloft on Sun will dry out the mountains, with
convection limited to the ern slopes of the Sangres/Wets/Pikes
Peak. For the I-25 corridor and the sern plains, post frontal
upslope will persist, keeping dewpoints in the 50s east of I-25
through the day. 0-6km shear of 35-45 kts will be in place,
with models showing CAPE in the 1k-2k J/KG range from afternoon
into the evening, while 70-80 kt jet streak at 250 moves
overhead late in the day. Set-up looks favorable for
strong/severe storms east of the mountains, though outflow and
potential cloud cover from Sat night/early Sun morning storms
could limit instability, especially into early/mid afternoon.
Current forecast has mainly isolated pops over the plains Sun
afternoon, then widespread storms along/east of I-25 Sun evening
as activity initially along the Palmer intensifies and expands
south and east. Max temps behind the front on Sun will run 5-10
degf cooler than Sat, while mountains see little change.

Low confidence forecast for Mon-Wed as model solutions have
bounced around a good deal, though rough consensus appears to
favor a return of low/mid level moisture to much of the area as
we approach mid-week, with western U.S. upper trough/sern U.S.
upper ridge pattern potentially reforming. Blended model
guidance shows cooler than average temperatures and daily
chances for showers/thunderstorms, which looks fine for now.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1141 AM MDT Thu Sep 17 2026

KCOS and KPUB: VFR conditions the next 24 hrs, with a prob30 for
a brief -tsra from late this afternoon into early this evening.
S-SW winds will increase at both terminals this afternoon, with
gusts to 20-25 knots expected. Winds then decrease overnight
into Friday morning.

KALS: VFR conditions are expected over the next 24 hours, with a
prob30 for -tsra from late this afternoon into this evening. The
main storm threats will be gusty winds to 35 kts and and brief
heavy rainfall. VCSH will linger until around 08z, then most
precip shifts east of the area. S-SW winds will remain gusty
(20-25 kts) this afternoon, before diminishing this evening and
overnight.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight MDT tonight for COZ067-068.

&&

$$

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