944
FXUS65 KPUB 190042
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
642 PM MDT Tue Jun 18 2024

.KEY MESSAGES...

- Non zero threat of thunderstorms and a few landspouts in Baca County
  this evening.

- Widespread rain showers and thick clouds across the eastern
  plains Wednesday, with some thunder over the mountains.

- Another warming trend late week into the weekend.

- Uptick in thunderstorms over the mountains late week as
  southerly flow picks up some subtropical moisture.

- A return to around 100 degree readings across the plains early next
  week.

&&

.UPDATE...
Issued at 641 PM MDT Tue Jun 18 2024

Quick update to the forecast database due to the expiration of
the Red Flag Warning for today. Incorporated latest HRR and
RUC model data as well as observations.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 242 PM MDT Tue Jun 18 2024

Rest of Today...

Relatively quiet weather for the first part of today across the CWA,
with the front already moving to our south. High temperatures will
be cooler than yesterday, with mid-80s to low-90s over the southeast
plains and low-80s across most of the higher terrain. Winds will be
occasionally gusty but less than yesterday, and humidity over the
plains has increased behind the front enough to abate critical fire
weather conditions for now. However, the Red Flag Warning will
remain this afternoon over the San Luis Valley, as the humidity
values out there are still low and were mostly unaffected from the
passing front.

Our potentially more active weather will happen this evening, as the
front stalls out just south of our forecast area. The positioning of
the front will be crucial to how much activity we actually see, as
convective models show a line of thunderstorms forming along the
boundary and intensifying. The majority of models currently show the
convection initiating south of our area and largely staying there,
however a shift in position just a few miles north could put some
storms in Baca County. For any stronger storms that do manage to
form over our far southeast plains, enhanced heavy rain, some hail,
and even a few landspouts will be possible.

Tonight-Wednesday...

With post-frontal moisture and lingering convection, wet and
unsettled conditions will persist overnight and into early
Wednesday. Scattered showers and heavy rainfall will spread across
parts of the eastern plains, becoming more widespread the closer you
get to the KS border. A few stronger storms will be possible, mainly
over our far southeast counties. Precipitation will continue to
build west through the night and into the early morning hours, with
rain moving over I-25 around sunrise. Showers will start to decrease
in coverage closer to the mountains as we move into Wednesday, but a
low, thick cloud layer will last into the day.

High temperatures on Wednesday will be around 15 degrees cooler than
Tuesday, possibly even cooler in some areas thanks to extensive
cloud cover. The mountain valleys will not see the full impact of
the front, remaining in the high-70s to low-80s. Meanwhile, the
moist post-frontal airmass will remain in place with easterly
upslope over the plains. More stratiform-type rain showers will
spread over most of the eastern plains throughout the day, and
though there could be an embedded rumble of thunder, instability
will likely be too low. Southwest flow aloft should assist in some
weak thunderstorm formation over the mountains, with some locally
heavy rainfall being the main concern. Storms over the mountains
should stay sub-severe, though locally heavy rainfall could have
some impacts in more vulnerable locations.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 242 PM MDT Tue Jun 18 2024

Temperatures gradually warm again through late week as southerly
flow ahead of the next Pacific trough brings rising heights
aloft over CO. The warm up will be somewhat mitigated by an
influx in subtropical moisture as the H7-H5 layer specific
humidities increase to 6+ g/kg. This will bring an uptick in
thunderstorms to the mountains especially Thursday and Friday.
Day time humidity values will increase as well which should put
an end to critical fire weather conditions for a while, but
raise concerns for heavy rainfall on burn scars. Mean CAPE
values off national model blends are highest on Thursday ranging
from 500-1000 J/kg in the 50-75th percentiles and ranges. They
drop around 250 J/kg for Friday. Storm motions will be to the
north due to deep southerly flow aloft. A few strong storms will
be possible over the mountains where deep layer shears will be
around 30+ kts both days. Hail under 1 inch in diameter and wind
gusts up to 50 mph will be possible. Best forcing will be late
Friday as the dampening western U.S. upper trough ejects across
NW CO. This may keep some showers and isolated thunderstorms
going most of the night across the mountains though intensities
will be weaker with loss of heating during the overnight hours.

Drier and warmer weather returns for the weekend into next week as
the upper ridge aloft builds over the southern/central U.S. Rockies.
Temperatures will be back up to around 100 across the plains for
Monday and Tuesday. Probabilities for afternoon and evening showers
and thunderstorms gradually decrease though winds look to stay below
critical fire weather thresholds. -KT

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 548 PM MDT Tue Jun 18 2024

KALS: VFR conditions are expected over the next 24 hours. Winds will
remain relatively light overnight, and then start to increase during
the early afternoon. Mid level clouds will also start to increase
some during this TAF period, but dry conditions are anticipated
through tomorrow.

KCOS and KPUB: VFR conditions are expected through this evening,
with MVFR conditions developing overnight and persisting through
much of this TAF period, primarily due to low clouds. Speaking of
clouds, mid to low level clouds will develop overnight and remain in
place through much of this TAF period, with minor lifting/thinning
of clouds possible near the end of this TAF period. Along with that,
drizzle to light rain is expected as moist east to southeast upslope
flow prevails. Otherwise, pockets of light precipitation are
expected around both TAF sites through much of tonight and
tomorrow.

&&

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

&&

$$

UPDATE...MOORE
SHORT TERM...GARBEROGLIO
LONG TERM...KT
AVIATION...SIMCOE