673
FXUS65 KPUB 110926
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
326 AM MDT Tue Mar 11 2025

.KEY MESSAGES...

- Dry and mild with a bit more cloud cover today, along with
  spotty critical fire weather conditions across the San Luis
  Valley.

- Dry for most Wednesday, with spotty critical fire weather
  conditions possible.

- Strong Spring storm system still expected Thursday -
  Saturday, with highest impacts Thursday and Friday.

- Warmer and drier pattern for the end of the weekend and start
  of next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 319 AM MDT Tue Mar 11 2025

Currently...Weak westerly flow aloft was in place across the region,
while an upper low approached the southern CA coast. Mostly clear
skies were evident across southeast and south central CO early this
morning, with temperatures as of 2 AM dipping into the teens and 20s
for the San Luis Valley, 30s for the Upper Arkansas River Valley,
and 30s and 40s for the eastern plains.

Today and tonight...The flow aloft will shift to a more southwest
direction this afternoon and evening as the Pacific upper low moves
onshore, then weakens as it nears the Four Corners. While conditions
are expected to remain dry through the short term, there will be an
increase in mid and high level cloudiness, keeping max temps today a
few degrees cooler than those experienced on Monday. However, it
will still be a warm day with temps above seasonal normals, as well
as minimum humidity levels this afternoon likely to drop below 15%
for most locations. So, warm and dry, but the limiting factor will
be the lack of stronger winds. Model guidance is indicating H7 winds
at around 20 kts this afternoon, but with increasing cloud cover
deeper mixing may be hindered. The one location of concern will be
the San Luis Valley, where there is a growing area of enhanced fire
danger between 3 PM and 6 PM today. However, this is a very
borderline event. Therefore, will not issue any fire weather
highlights for today and will instead make mention of concerns for
the San Luis Valley in the Fire Weather zone forecast discussion.

Plan on highs today in the mid 50s to around 60F for the high
valleys, and 60s to lower 70s for the plains. Tonight, overnight
minimum temps are forecast to cool into the teens and 20s for the
high valleys, and 30s for the plains. Moore

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 319 AM MDT Tue Mar 11 2025

Wednesday: For midweek, relatively quiet weather is expected for
south central and southeastern Colorado. An open shortwave will pass
over the region throughout the day, though the core of the wave will
remain further south. While stronger forcing will remain further
south, a slight uptick is expected for the area, and given this,
along with a minor increase in moisture late in day, isolated light
snow showers will be possible along the higher terrain. Elsewhere
dry conditions will prevail. Beyond all of that, occasional pockets
of mid to high level clouds and breezy winds are anticipated. In
addition, spotty critical fire weather conditions are expected
across the plains given the breezy winds and low humidity values. As
for temperatures, a mild Spring day is in store, with much of the
area warming to around and slightly above seasonal values for mid
March.

Thursday - Saturday: For the later part of the week, a strong Spring
storm system is still expected to influence south central and
southeastern Colorado. Overall, not much has changed in the way of
thinking; a large trough will approach on Thursday, push over the
region Friday, and exit Saturday night. As this system approaches
Thursday, precipitation chances will increase along the higher
terrain throughout day and then spread across the valleys overnight,
then become more widespread Friday, and finally start to decrease
Saturday night from west to east as the broader trough pushes
eastward. The heaviest precipitation is expected Thursday and
Friday, and is expected to remain along the higher terrain where
forcing will be maximized. Given the anticipated strength of the
system, moderate, to at times heavy, wind driven snow is anticipated
along the mountains, especially Thursday and Friday. Along with all
of that, a rapidly deepening lee cyclone is still expected Friday as
the base of the trough and left exit region of the associated jet
streak push over. While some disagreement still exist within model
guidance, a trend towards putting the low over west central Kansas
by early Friday afternoon is evident, which will allow for the
potential of high impact weather to influence the region. This
lee cyclone will bring strong winds to much of the area,
especially along and east of the eastern mountains. In addition,
this feature will have a large impact on how the precipitation
across the plains materializes. This storm system is not
expected to have a lot of cold air with it, and this will limit
how much cold air can wrap into the deepening lee cyclone.
Ultimately this will affect how low snow levels will drop,
generally around 5,500 ft, when precipitation chances will be
greatest for the plains during Friday. What this means is areas
generally above this level will be a sloppy, wet, slushy snow,
while areas generally below this level will be all rain. With
that all said, confidence does remain high (80%) in the
development of this feature, with now medium (50-60%) confidence
in the location and strength of the lee cyclone given decent
agreement between ensemble model guidance. In addition to all of
that (yeah there`s more, but that`s a Spring storm system in
Colorado for ya) increased fire danger is possible Thursday
ahead of the approaching trough. As winds increase in response
to the arriving system Thursday, and low humidity values develop
during the day, critical fire weather conditions may become a
concern Thursday across much of the eastern plains. Outside of
all of that, increased cloud cover is anticipated throughout
this period, with general gusty winds during this timeframe.
Looking at temperatures, Thursday will be the warmest, with
downsloping winds warming the region ahead of the storm system.
Then for Friday and Saturday, cooler air does start to filter
in, especially for Saturday, with much of the area below
seasonal temperatures.

Sunday - Monday: For the end of the weekend and start of next week,
quieter weather makes a return to south central and southeastern
Colorado. Behind the late week storm system, ridging is anticipated
to develop, and with the increased descent and drier air with this
pattern, dry conditions are expected to prevail. The exception to
this may be Monday night, as showers start to blossom again along
the higher terrain as another storm system approaches. Otherwise,
breezy conditions are expected, especially Monday as the next system
approaches, with pockets of mid to high level clouds. Temperatures
during this period will start to warm, but especially Monday, as
downsloping winds overspread the region, with above seasonal
temperatures anticipated.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 319 AM MDT Tue Mar 11 2025

VFR conditions anticipated over the next 24 hrs for the forecast
area, including the three main TAF sites of KPUB, KCOS and KALS.
Winds will start to pick up at KALS and KCOS around 21Z, with gusts
to around 20 kts lasting for a few hours before diminishing
overnight.

&&

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

&&

$$

SHORT TERM...MOORE
LONG TERM...SIMCOE
AVIATION...MOORE