Fort Lyon, Colorado Weather Forecast Discussion

191
FXUS65 KPUB 170953
AFDPUB
Area Forecast Discussion
National Weather Service Pueblo CO
353 AM MDT Wed Sep 17 2025
.KEY MESSAGES...
- An incoming system will bring showers and thunderstorms to the
  area today, with some strong to severe expected.
- Moisture begins to dwindle on Thursday with another day of
  cooler temperatures.
- Warmer and drier from Friday through the weekend into early
  next week, with just some very isolated afternoon
  thunderstorms possible over the mountains.
&&
.SHORT TERM /THROUGH THURSDAY/...
Issued at 316 AM MDT Wed Sep 17 2025
Today and Tonight...
Upper-level trough will continue moving through our region today,
bringing another round of cooler and relatively active weather.
Initially, leftover cloud cover from yesterday`s convection will
keep things largely cool and stable across the area. That being
said, easterly upslope will set in by mid-afternoon. With strong
westerly winds aloft and ample low-level moisture, another round of
showers and thunderstorms is expected to form, mainly along the
mountains/plains interface. Storms will generally move east-
southeast, following the steering flow from the main trough axis
overhead. Looking at severe parameters, modest instability and 30+
knots of bulk shear indicate a good chance for some strong to severe
storms. The entirety of the eastern plains is under a marginal
outlook, with some areas along and south of Highway 50 under a
slight, where the highest CAPE values are in the models at 1500 J/kg
or more. Models have also trended down throughout the last 12 hours
in regards to morning cloud cover. In all, some enhanced daytime
heating, combined with sufficient CAPE and robust shear profiles,
could make for some interesting afternoon thunderstorms.
More likely than not, storm formation will be mostly limited to
elevated heating surfaces (the mountains, Palmer Divide, and Raton
Mesa), as well as along any outflow boundaries later in the day. The
shear in place may keep storms moving, and the longer-lasting cells
may be able to travel southeast and take advantage of the better air
to intensify. Stronger storms over the plains could produce some
strong outflow, hail to 1 inch, and briefly heavy rain. Over the
southeast plains, where the best environment will be, intensified
storms could produce stronger outflow winds and large hail.
Additionally, given the shear profiles, an isolated tornado or two
cannot be ruled out.
Finally, temperatures will be noticeably cooler than yesterday.
While high temperatures in some places will be dependent on cloud
cover, we will generally be seeing 70s to low-80s over most of the
forecast area.
Thursday...
Upper trough moves east on Thursday, leaving breezy northwest flow
aloft. Still seeing enough lingering moisture at the low to mid-
levels for another round of afternoon showers and storms. However,
shear in the afternoon will be a bit lower with a less supportive
vertical profile. This, along with slowly decreasing instability,
will mean that any convection on Thursday will generally be weak to
moderate at best. Latest guidance shows some scattered afternoon
coverage, mainly tied to the Palmer and Raton areas. Temperatures
will be cooler still thanks to the passing system, falling just a
bit below seasonal averages. Expect highs in the high-60s to mid-70s
across most of the area.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 316 AM MDT Wed Sep 17 2025
Upper low departs and ridge builds on Friday, with warmer
temperatures and only some isolated/weak convection over the
higher terrain along the NM border. Main change to Friday`s
forecast was to nudge max temps upward a few degf at many
locations, as NBM looked too cool given warmer more recent 00z
statistical guidance. Upper ridge flattens a bit over the
weekend, allowing leftover mid-level sub-tropical moisture to
drift into the state, which will in turn drive an increase in
mountain convection both Sat/Sun. Storm intensity/coverage
look weak/isolated through the period, with mainly lighting,
wind and light rain/sprinkles with most activity.
Ridge rebuilds over Rockies early next week, keeping warm
weather in place while moisture and thunderstorm chances
decrease. Some potential for a cold front by mid-week as short
wave energy crests the ridge and dives into the central U.S.,
though model spread on details/timing are rather large at this
point.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 316 AM MDT Wed Sep 17 2025
Mainly VFR conditions remain expected at COS and PUB over the next
24 hours. A upper trough will continue to move across the Rockies
through the period, with one piece of the system keeping showers and
storms across the Pikes Peak region into the mid Arkansas River
Valley at this time. Storm potential clears COS and PUB by 08Z, with
clearing skies through the early morning hours. Passing front will
keep breezy northerly winds 10-20kts into the early morning hours
before winds weaken and become more easterly through the day
Wednesday. This will bring in VFR cigs once again aft 18Z, with
another round of showers and storms expected into Wednesday evening,
with brief MVFR conditions possible with the strongest storms.
VFR conditions are expected at ALS over the next 24 hours, with
breezy south to southwest 10-15kts and some cloud buildups over the
higher terrain through the afternoon.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...GARBEROGLIO
LONG TERM...PETERSEN
AVIATION...GARBEROGLIO

NWS PUB Office Area Forecast Discussion