759
FXUS65 KPUB 080952
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
352 AM MDT Sat Jun 8 2024

.KEY MESSAGES...

- Strong to severe thunderstorm activity is expected across most
  of the eastern plains today, with all hazard types on the
  table.

- Thunderstorms, a few strong, possible Sunday and Monday across
  the mountains and adjacent plains with risks transitioning
  towards hail and heavy rainfall capable of producing localized
  flash flooding.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 343 AM MDT Sat Jun 8 2024

Today will be a more active weather day as energy translates through
the mid-level flow. Along with moist post-frontal air, the large-
scale ascent will allow for the formation of convective weather in
our forecast area this afternoon.

Post-frontal upslope will persist across the eastern plains starting
this morning, pairing with that synoptic ascent to get us primed for
precipitation formation. Looking at model variables in support of
severe weather, there are a few differences but an overall
consistent signal. CAPE will increase over the plains throughout the
day, with the model spread typically between 500-1000 J/kg. Higher
values will be possible near the border, with around 1200 J/kg in
some of the high-res models. Looking at shear parameters, the model
spreads are typically between 25-35 knots this afternoon. With
many of the convective allowing models leaning towards the
higher end of the CAPE estimates and modest wind shear at the
low levels (0-6km), strong to severe storms and multiple severe
hazards will be on the table this afternoon into evening.

There are a few main areas of concern, the first being the northern
half of our forecast area, east of the mountains. Better mid-level
shear will be available just north of our area, and high-res model
guidance has been consistently developing a line of thunderstorms
off of the higher terrain that intensifies as it moves east. The
southern extend of this line will reach down, depending on which
model you look it, into Kiowa County and potentially into the
Highway-50 corridor. For these areas, strong winds, heavy rain, some
hail, and isolated tornadoes will all be possible, especially along
the southern edge of that line. Meanwhile, largely south of Highway
50, more isolated convection will be possible, with a mix of severe
hazards possible, though the magnitude of the severe impacts will
decrease further south. Looking over the mountains, while convection
will generally be much more scattered in nature today, cannot rule
out flash flooding concerns over a burn scar or other vulnerable
area, especially if several cells train over the same areas.
Additionally, more discrete cells left behind the passing line of
convection or influenced by outflow interactions could also result
in lingering severe hazards late this evening and into tonight.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 343 AM MDT Sat Jun 8 2024

Day 2 post frontal upslope flow will be in place for Sunday with the
morning starting out with areas of stratus banked up across the
lower eastern slopes of the southeast mountains, southeast plains
and southern slopes of the Palmer Divide.  Flow aloft weakens some
on Sunday which will decrease deep layer shears to around 20-25 kts
by afternoon.  However sustained dew points in the 50s pushed
westward into the eastern slopes of the SE mts/Fremont county will
provide the fuel for CAPEs up to 1500 J/kg based off HREF means.
Weak energy propagating through the ridge aloft, along with surface
based heating, will be sufficient to trigger scattered to numerous
showers and thunderstorms across the mountains which will drift off
into the adjacent I-25 corridor in the afternoon and plains through
the evening.  Some question exists as to amount of instability
across the plains as soundings look pretty capped, especially the
farther east you go.  However with southerly upslope into the Palmer
Divide, forcing may be enough for thunderstorms to maintain as they
move eastward.  Heavy rainfall and hail up to 1.25 inches look
possible with any storms in and near the mountains and the Palmer
and Raton ridges.  Farther east, suspect risk will transition to
smaller hail heavy rainfall as shear looks too weak for strong
updraft maintenance.  Will need to watch the southeast mountains,
Pikes Peak region, and burn scars for potential flash flooding,
especially as creeks and streams are still running near bank full in
some locations due to snow melt.  Any localized heavy rainfall could
exacerbate conditions, though think this will stay localized and
therefore may not require any flash flood watches.  Forcing for
nocturnal thunderstorm maintenance appears to stay to the south of
the area overnight in better proximity to the frontal boundary, with
most thunderstorms ending by midnight. Pacific energy lifting
northward through the ridge across NM may spread some showers and
thunderstorms into far southern plains overnight but CAPE doesn`t
look all that substantial, so some lightning and rainfall will be
the main risks.

One more day for scattered to numerous showers and thunderstorms can
be expected for Monday as the remnant Pacific energy cuts through
the upper ridge and a northern stream system brushes by to the
north.  Overall, 0-6 km shears will be even weaker, so thunderstorms
will be limited to locally heavy rainfall, small hail and gusty wind
risks as they develop over the mountains early in the day and
diminish as they move eastward into a more stable airmass across the
plains.  Monday looks to be the coolest day across the region.

Upper ridging returns for mid week with thunderstorm chances
decreasing and transitioning more towards higher based thunderstorms
with a gusty wind potential.  Temperatures will approach 100 again
on the plains especially towards Thursday.  Another Pacific system
will approach CO on Friday.  This will bring another uptick in
showers and thunderstorms to the region and take the edge of max
temperatures.  Saturday returns to drier and warmer conditions as
models are in better agreement with the upper system exiting to the
east. -KT

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 343 AM MDT Sat Jun 8 2024

VFR conditions are generally expected at KALS, KCOS, and KPUB
through 24 hours. Showers and thunderstorms will form across the
area this afternoon, with storms expected to drift near both KCOS
and KPUB. Storms over the terminals will result in briefly reduced
visibility, while nearby storms will cause erratic outflow winds
gusting in excess of 40 knots through this evening. Stronger storms,
while mainly expected further east, will be capable of producing
outflow winds around 50 knots. Storms will end later this evening
into the overnight hours, with conditions calming closer to the end
of this forecast period.

&&

.HYDROLOGY...
Issued at 343 AM MDT Sat Jun 8 2024

Rapid snow melt will continue across the mountains leading to
elevated flows along the Arkansas River from Leadville to Canon
City through Monday as well as on smaller creeks and streams in
and near the mountains. Flows are expected to remain within
banks for most locations along the Arkansas River but fast flows
can still be dangerous. Slightly cooler temperatures may
decrease the snow melt Sunday and Monday, however the potential
for heavy rainfall will increase both days for the southeast
mountains and adjacent plains. This could cause localized flash
flooding and push flows above the projected bank full forecast
for localized areas depending on where the rain falls.
Latest projections place the heaviest rainfall across Teller,
western El Paso and Fremont counties on Sunday though the flash
flood risk still looks localized. Continue to monitor weather
forecasts closely.

&&

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

&&

$$

SHORT TERM...GARBEROGLIO
LONG TERM...KT
AVIATION...GARBEROGLIO
HYDROLOGY...KT