258
FXUS65 KPUB 301740
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1140 AM MDT Thu May 30 2024

.KEY MESSAGES...

- Strong to severe storms are possible (40-60%% chance) for our
  plains today, with main risks being hail up to 1.5 inches in
  diameter, winds gusting to 60 mph, and lightning.

- Still a risk of strong to severe storms on the plains both
  Friday and Saturday, as low level moisture remains in place.

- Mainly dry and hot from Sunday into the middle of next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 333 AM MDT Thu May 30 2024

Currently..

Showers and storms have pushed east, though satellite imagery and
area observations show that stratus is developing again across EL
Paso County early this morning. KFLY was reporting BKN004 ceilings
as of 3am. With lingering moisture from today`s rain and outflow
boundaries, thinking we could, again, have lots of moisture to work
with for today`s convection. Temperatures and dew points are both
ranging from 40s to 50s across the plains this morning.

Today and Tonight..

The SPC has a very similar outlook for our plains as what we saw for
yesterday, with a slight risk for strong to severe thunderstorms
across areas generally east of I-25 this afternoon and into this
evening. Today`s convection will be highly dependent on available
moisture, and upon the influence of a cold front that looks to make
its way into northern portions of the area in the next hour or two,
and work its way across the plains throughout this morning. Surface
winds look to shift around to easterly by the early afternoon hours,
which could help to usher in more moisture as well. Instability is a
bit less than yesterday, though most areas are still looking at
around 1500 J/kg or so at least. High res models are keeping higher
end CAPE values closer to 2,200 J/kg out on our far eastern plains
for today. Another difference is that shear is overall a bit less
than yesterday, closer to 30kt instead of 40kt. Helicity is also
much less impressive than yesterday, giving an overall impression
that our landspout and tornado threat would be closer to zero than
we were for yesterday on our eastern plains. Isolated weak storms
get going late this morning over the high country, where gusty wind
and lightning will be the main concerns. Stronger storms look to
develop earlier across out southern plains, with strong to severe
storms possible over portions of Las Animas and Baca counties as
early as 1 pm this afternoon. CAMs depict another round of storms
firing over the Pikes Peak region by around 2pm or so, with storms
filling in across the I-25 corridor as they advance southeastward
throughout the afternoon and evening hours. Models tend to keep
convection on our plains through the evening and into the overnight
hours once again, though most areas look to be dry by around
midnight or so at the lastest. Given the increase in moisture and
possible effects of the frontal influence, thinking that we could
have more coverage than yesterday. Given the decrease in shear,
thinking that today might be slightly less in intensity than where
we for yesterday. Main risks with stronger storms will be large hail
up to 1.5 inches, wind gusts to 60 mph, and lightning. Other than
today`s thunderstorm potential, expect another day of slightly above
normal temperatures, sunshine, and mostly light easterly winds until
thunderstorms begin to develop. Temperatures for today look to be
around 3 to 5 degrees cooler for most plains locations behind the
passing cold front, with highs topping out in the mid 70s to mid
80s. Mountain valleys will be around the same as yesterday, with
highs in the mid to upper 70s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 333 AM MDT Thu May 30 2024

Friday and Saturday now look like more active convective days on
the plains than previously thought, as low level moisture and
instability are slow to be shunted eastward. On Friday, progged
CAPE is in the 1000-2000 J/KG range, while 0-6km shear is around
30-35 kts. No definitive wave evident to spark convection, but
still enough weak energy to aide in mountain storms by mid-
afternoon, then activity strengthens as it moves east of I-25
and encounters a much more unstable air mass. SPC has introduced
a marginal risk of severe storms for most of the southeast
plains for Friday afternoon, which appears reasonably. Pattern
continues Saturday, though storm strength and coverage on the
plains may increase, as at least a few model solutions show
large instability on the order of 2000-3000 J/KG and 0-6km
shear of 35-45 kts, which would produce supercells and big hail
if they verify. SWODY3 now has slight back over all of the
southeast plains, which is an upgrade from previous forecasts.
Haven`t mentioned the mountains and interior valleys much,
though their forecast hasn`t changed much, with sparse/weak
afternoon convection both Fri/Sat, producing more wind than rain
and most locations. Temps all areas Fri will run near seasonal
averages on Fri, then climb several degf on Sat as mid level
warm and mixing deepens.

Upper trough swings through the Rockies late Sat into Sun,
bringing deepening sw flow and drier air to much of srn
Colorado. Moisture should be shunted far enough east to
eliminate thunderstorm chances for most of the region Sunday,
though will have to watch areas near the KS border for potential
storm initiation as dryline won`t be too far away. Max temps
Sunday will soar with deep mixing and mid-level thermal ridge
overhead, with readings deep into the 90s on the plains, 70s/80s
mountains and valleys. Weak cold front late Sun into Mon may
shave a few degf off of max temps Mon afternoon, though doesn`t
appear we`ll have enough a westward push of low level moisture
for any convection at this point. Models then build upper ridge
somewhere over the western U.S. next week, with deterministic
ECMWF and its ensemble farther west than GFS family of solutions.
As a result, GFS solutions look very hot and dry with ridge
overhead, while farther west Euro has a couple of cold fronts
and slightly cooler air sliding through the plains by mid-week.
In either case, main message of the forecast for next week is
for warm temperatures and generally dry conditions, with the
amount of heat still somewhat of a question.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1139 AM MDT Thu May 30 2024

VFR conditions are expected to prevail for KALS and KPUB, and mostly
for KCOS, throughout the forecast period. SHRA and TSRA are expected
to be in and around the vicinity of KCOS and possibly KPUB by later
in the afternoon and through the evening, with a better chance of
occurrence at KCOS. There is also a slight chance of VCSH/VCTS for
KALS, although confidence of this is low and therefore was left
out of the TAF at this time. If SHRA/TSRA does develop, it
could temporarily reduce CIGs and VIS to MVFR/IFR criteria. It
could also result in periodic windshifts and increased wind
speeds. Winds will be mostly synoptically influenced throughout
the day due to a passing upper level through OVHD, but then
become more diurnally influenced by later in the evening as
winds diminish. For KCOS and KPUB, there will also be a threat
of GR, mainly between 20Z to 00Z.
-Stewey

&&

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

&&

$$

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