087
FXUS65 KPUB 171744
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1144 AM MDT Sun Aug 17 2025

.KEY MESSAGES...

- Upper ridge shifts slightly eastward today, bringing drier air
  and lower chances for thunderstorms to the region.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 325 AM MDT Sun Aug 17 2025

Today and Tonight...Upper-level ridge moves east into the plains,
with main plume of higher moisture shifting south and east of the
region. As a result, we should see a general drop off in
thunderstorm activity across the area as moisture/instability
decrease, with mainly isolated, high based storms over the
mountains. Sliver of slightly higher instability (CAPE 500-1000
J/KG) possible over the far sern plains where se surface winds allow
for slightly higher dewpoints to linger, and CAMs hint at a few
storms over ern Las Animas/Baca Counties from late afternoon into
early evening, before activity dissipates 02z-03z. Deep layer shear
looks weak, so main risks will be gusty outflow winds and lightning
with any stronger storms. Sunday`s high temperatures will drift
upward a couple degf over the mountains and valleys, while readings
on the plains stay withing a degf or two of Saturday`s numbers.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 325 AM MDT Sun Aug 17 2025

Monday and Tuesday:

Showers and thunderstorms are expected to develop Monday afternoon
with some of the storms could be strong to severe over the Pikes
Peak Region and over and near the Raton Mesa in Las Animas County.
The primary hazards I am concerned about are gusty outflow winds of
up to 40-50 MPH. LCLs are around 10kft, so the precipitants have
very far distance to fall in a dry environment (more evaporation ->
evaporational cooling -> stronger downdraft). CAPE values are
expected to be below 1000 J/kg and deep shear values are around
30kts - not terribly concerned about organized convection producing
hail. Lingering weak thunderstorms will last through around
midnight, but minor impacts are expected.

Tuesday is expected to be the last day for isolated to scattered
thunderstorms before a brief dry spell occurs. The limiting factor
to how strong convection gets will be how much moisture from the
eastern plains is advected towards the plains-mountains interface.
Currently, the majority of guidance has sub 1000 J/kg of CAPE along
the eastern mountains and the I-25 corridor, but the aggressive NAM
has 1500-2000 J/kg of MUCAPE (which I do not believe). Overall,
another I think the main hazards will be gusty outflow winds from
high based thunderstorms along the I-25 corridor.


Wednesday through Saturday:

The upper level high sets up over the four corners region of the
desert southwest and begins to advect moisture from the eastern
Pacific / Baja California towards southern Colorado. While we wait
for that moisture to reach Colorado, we`ll have two dry days with
Wednesday and Thursday. The trend has been having an uptick in storms
on Thursday, but the brunt of the moisture will arrive on Friday.
Some persistent signals amongst longer term guidance is suggesting
heavy rain over the mountains and the I-25 corridor on Friday and
Saturday - perhaps this is mountain flash flood event beginning to
show its eyes for the end of next week and into the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1139 AM MDT Sun Aug 17 2025

VFR conditions expected over the next 24 hours with isolated
thunderstorms forming across the southeast plains, likely to the
east of both the KCOS and KPUB terminals, or staying over the
mountains to the west and east of KALS. All three TAF sites will
remain dry with no mention of -TSRA for now. Gusty outflow winds
will be the primary storm risks with any storms that do form.
Winds will generally be diurnally driven with speeds under 15
kts. KCOS and KPUB will likely see an east to southeast wind
during the evening as weakening outflow from thunderstorms
across the far southeast plains works its way westward towards
the mountains, but for now, don`t think speeds will exceed 15
kts at the terminals. -KT

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...PETERSEN
LONG TERM...SKELLY
AVIATION...KT