864
FXUS65 KPUB 291727
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1127 AM MDT Wed May 29 2024

.KEY MESSAGES...

- Strong to severe storms are likely (60-80% chance) for our
  plains today, with main risks being hail up to 2 inches,
  winds gusting to 60 mph, and lightning.

- Severe storms possible on the plains Thursday
  afternoon/evening.

- Scattered afternoon storms again Friday/Saturday, though less
  chance of severe weather.

- Generally dry and warmer from Sunday into next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 345 AM MDT Wed May 29 2024

Currently..

Upslope conditions have developed across portions of El Paso, Pueblo
and Fremont counties this morning, as east-southeasterly winds and
outflow enhanced moist air have made their way westwards and back
into the terrain. Ceilings are around 1,500ft across El Paso County
as of 3am. Dewpoints are in the 40s, and temperatures are in the
50s. This extra moisture will help to set the stage for today`s
convection.

Today and Tonight..

Models show the upper ridge axis passing overhead early this
morning, as a trough begins to push into the Northern Rockies later
on this morning and into this afternoon. This pattern, along with
our influx of moisture, will help to spark a few storms over the
high country by around 11 am. Higher storm coverage and intensity
will exist over northern and southern portions of our mountain
adjacent plains by around 1pm this afternoon. Some models don`t seem
to be realizing the amount of moisture that we could be working with
today, though CAPE values are still ranging from around 1500 to 3000
J/Kg throughout this afternoon and this evening. 0 to 6km shear is
anywhere from 30 to 40 kts as well, with highest amounts further out
out on our plains. In many ways, today will be similar to yesterday,
with two rounds of storms firing over our southern plains and the
Pikes Peak region, and eventually joining up over our eastern
plains, and with 2 inch hail and 60 mph wind gusts being our biggest
concerns. The main difference will be that today we could see more
of a non-zero tornado or landspout threat. 0 to 3km Helicity indexes
are not super impressive, but are higher than yesterday, especially
over the Palmer Divide later this afternoon and into this evening.
Daytime high temperatures will be a couple of degrees warmer than
yesterday for most locations. Storms are expected to linger a bit
later than they did yesterday for our eastern plains, though most
locations should still be dry by midnight.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 345 AM MDT Wed May 29 2024

Upper level wave swings eastward out of the northern Rockies
into the nrn plains Thu, with southern extension of the wave and
associated upward motion moving across Colorado during the day.
Main question for Thu revolves around the evolution of the
surface air mass over the southeast plains, as nrn Rockies wave
pushes a cold front through the area Thu morning, with boundary
becoming nearly stationary along the CO/NM border in the
afternoon. Behind the boundary, northerly winds in the morning
gradually turn eastward during the afternoon, leading to
increasing low level moisture and instability (CAPE in the
1000-2000 J/KG range) for most of the area east of I-25 through
the day. Wrn edge of the deeper moisture/instability still
somewhat of a question, as a few CAMs are slower to turn the
winds easterly, which would keep deeper moisture/instability
closer to the KS border versus farther west near/just east of
I-25. If winds turn easterly as progged, 0-6km shear by late Thu
afternoon will increase into the 35-45 kt range, which would
support fairly widespread severe convection and perhaps a few
supercells with large hail. Wind profile still not particularly
indicative of a tornado threat due to rather weak low level
winds, though a few landspouts may be possible during initial
cell development near the frontal boundary along the NM border.
Again, best chances for storm initiation will be along the
Palmer Divide and Raton Mesa, with perhaps some loose
organization into an MCS over the far east early in the evening
before activity rolls e-se into KS/OK/TX overnight. Mountains
and interior valleys will see scattered showers/thunderstorms,
but moisture continues to be rather sparse over the high
terrain, suggesting only spotty and light rainfall.

On Friday, still some moderate wind shear (0-6km of 30-40 kts)
in place across the area, though with cooler surface temps and
decreasing mid-level lapse rates, air mass will be considerably
more stable (CAPE in the 500-1000 J/KG range), leading to both
less thunderstorm coverage and weaker storms in general. Temps
warm Sat, but with even less moisture available, afternoon
convection will be weak and high based at most locations.

Very warm and dry conditions then forecast for Sunday as
mid/upper level flow turns more swly ahead of the weak upper
trough moving through the Rockies. Could see some mid-upper 90s
on the plains by Sunday afternoon, as dryline shifts toward the the
KS border and deep mixing develops along and east of the
mountains. Continued warm and dry into next week, as heights
gradually build over the swrn U.S. and best low level moisture
remains just to our east through the period.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1127 AM MDT Wed May 29 2024

VFR conditions are expected to prevail for all TAF sites (KALS,
KCOS, and KPUB) throughout the forecast period. There will be a
moderate probability of VCTS for KCOS and KPUB, with only a slight
probability of VCSH/VCTS at KALS. If SHRA/TSRA does develop, it
could temporarily reduce CIGs and VIS to MVFR/IFR criteria. Outflow
boundaries will be possible for both KCOS and KPUB during the late
afternoon through early evening hours due to convection, which may
cause abrupt windshifts. It could also result in periodic windshifts
and increased wind speeds if storms move over station. Winds will be
overall diurnally influenced towards throughout the forecast period.
-Stewey

&&

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

&&

$$

SHORT TERM...EHR
LONG TERM...PETERSEN
AVIATION...STEWARD