Lamar, Colorado Weather Forecast Discussion

946
FXUS65 KPUB 051758
AFDPUB
Area Forecast Discussion
National Weather Service Pueblo CO
1158 AM MDT Fri Sep 5 2025
.KEY MESSAGES...
- Much cooler today, with temperatures around 20 degrees lower than
  Thursday. Expect scattered to numerous showers/thunderstorms across
  the high country this afternoon and evening, lesser chances over
  the plains.
- Warmer Saturday, with afternoon showers and thunderstorms once
  again, especially over the mountains.
- A couple of strong to severe storms will be possible across
  the plains Sunday.
- Daily showers and thunderstorms are expected next week,
  though mostly along the mountains.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 325 AM MDT Fri Sep 5 2025
Initial cold front, aided by some outflow from weak evening
convection on the plains, was south of the NM border as of 2 am,
with north winds and cooler air spreading southward through the area
for the remainder of the morning. Immediate concern this morning
will be potential for thunderstorms on the plains, with several CAMs
showing pocket of instability and at least scattered storms along
and south of the Arkansas River from sunrise through about noon.
Elsewhere across the area, just some scattered showers/light rain
this morning, with areas of lower clouds and drizzle potentially
developing over eastern mountain slopes toward sunrise as surface
flow swings around to the southeast. Will boost morning pops on the
plains as a result, keeping low to moderate pops in place elsewhere.
This afternoon, precip chances decrease on the plains as air mass
stabilizes, while over the mountains/interior valleys, shower and
thunderstorm chances increase as moderate instability (CAPE 1000
J/KG) develops. Along and east of I-25, instability drops off
quickly as clouds and cooler air keep a lid on convection, so expect
showers and storms to weaken as they move off the higher terrain.
Activity will tend to end from north to south this evening, with a
few storms lingering over the mountains near the New Mexico border
until midnight, before fading away by early Saturday morning.
On Saturday, more sun and building upper ridge will lead to a quick
warm-up, with maxes back into the 80s on the plains. Moisture
remains in place, which will lead to a round of afternoon and
evening showers developing over the mountains, with activity
spreading into the I-25 corridor during the late afternoon hours.
Could see a few stronger storms Sat with more sun and greater
instability, though with stronger shear staying north and east of
the area, severe storm risk looks low at this time.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 325 AM MDT Fri Sep 5 2025
Saturday Night - Sunday: For the later part of the weekend, active
weather continues, particularly for Sunday. Synoptically, a
shortwave will be pushing over Saturday night, with northwest flow
then prevailing through Sunday. Forcing is expected to be heightened
Saturday night with the wave passage, and become more terrain
focused Sunday. Along with all of that, at least modest moisture
is expected to be in place. With broader forcing and moisture
in place Saturday night, lingering isolated to scattered showers
are anticipated, though mostly across the valleys and
mountains. Then for Sunday, showers and thunderstorms are
expected to blossom along the higher terrain and push across the
valleys and plains during the afternoon hours. In addition, a
couple of strong to severe storms will be possible across the
plains Sunday, where at least modest shear around 30 knots is
expected to overlap with heightened moisture and instability.
If any storm can become organized enough, strong outflow winds
and large hail would be the primary hazards. Beyond all of that,
relatively light winds are anticipated Saturday night, with
breezier winds Sunday afternoon, and mostly clear skies Sunday
morning becoming partly to mostly cloudy through the afternoon.
As for temperatures, near to slightly below seasonal values are
expected for much of the region.
Monday - Thursday: For the rest of the long term period, active
weather is anticipated for portions of south central and
southeastern Colorado. Flow will become predominantly southwesterly
as troughing develops to the west of ridging to the east/southeast.
This will allow for persistent orographic forcing to be in place,
along with allowing for persistent moisture advection over the area.
With both forcing and moisture heightened, daily showers and storms
are expected, though with the greatest coverage remaining along the
mountains where forcing will be maximized. Outside of that, winds
will start to become breezy as increased flow sits over the region,
with periods of increased cloud cover during the afternoons. Looking
at temperatures, a warming trend is anticipated thanks to
downsloping winds, with much of the area warming back to above
seasonal values by mid week.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1157 AM MDT Fri Sep 5 2025
KCOS and KPUB...IFR to MVFR conditions are likely to persist off and
on at both KCOS and KPUB as showers look to pass through both
stations throughout the day. Improving conditions are likely at both
stations through the late afternoon and evening hours as some
clearing tries to move in, though persistent upsloping is expected
to bring ceilings back down through the overnight hours of tonight
into early Saturday morning. Mist and potentially fog will be
possible at KCOS as well, though confidence in FG was too low to
include in the TAF at this time.
KALS..Showers and weak thunderstorms have begun to form over
northern portions of the San Luis Valley, and are likely move over
and in the vicinity of KALS off and on throughout much of the
afternoon hours. Brief reductions to MVFR visibilities and ceilings
will be possible during shower and thunderstorm activity today, with
improvement likely after 01Z this evening. Depending on rainfall
amounts with afternoon convection, IFR ceilings and mist will also
be likely through the morning hours of Saturday at KALS as well.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...SIMCOE
AVIATION...EHR

NWS PUB Office Area Forecast Discussion