882
FXUS65 KPUB 221109
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
509 AM MDT Tue Apr 22 2025

.KEY MESSAGES...

- Thunderstorm chances ramp up Tuesday and Wednesday, especially
  across the plains.

- Thunderstorm chances continue Thursday into Friday across the
  Plains.

- Elevated fire weather conditions Thursday and Friday across
  the San Luis Valley, will spread east across the Plains over
  the weekend.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 316 AM MDT Tue Apr 22 2025

Weak impulses will ride through southwest flow aloft across CO over
the next couple days bringing daily afternoon and evening showers
and thunderstorms.  Surface dew points remain low on Tuesday,
generally in the teens and 20s, with inverted V soundings suggesting
high based afternoon showers and possibly a thunderstorm or two over
and near the mountains.  Gusty erratic winds will be possible near
these high based showers as they drift off the higher terrain.
Otherwise, high temperatures should be similar to today with
readings in the 70s to near 80 across the plains, 60s valleys, and
40s and 50s mountains.  Most high res models diminish precipitation
as showers move east across the plains, though can`t rule out an
isolated sprinkle towards the KS border during the late evening.
Otherwise, expect some residual cloudiness to keep overnight lows on
the mild side.

A cool front pushes into the southeast plains on Wednesday with
easterly surface flow advecting 40 dew points back westward into
the southeast mountains by afternoon with lower 50s possible near
the KS border. Question will be how quickly this moisture returns
for the southeast plains and where the axis of higher
CAPE/instability will be.  HREF Mean CAPE shows anywhere from
750 J/kg across Crowley and Otero counties to 2000 J/kg along the KS
border.  High res models suggest 2 areas of thunderstorm
development...along the Palmer Divide and along a surface boundary
setting up along the Raton Mesa extending northeastward across northern
Baca and southern Prowers counties. Easterly surface flow beneath
southwest flow aloft will yield around 40 kts of deep layer shear,
and HREF shows an area of helicity swaths across the eastern most
counties of Bent, Prowers and Baca counties.  Hail and damaging
winds will be the primary risks with a lot of details hinging on
where the boundary sets up in the afternoon and how quick the
moisture returns.  Otherwise, temperatures will top out in the 70s
again across the plains with 60s for the valleys and 40s and 50s for
the mountains. It will be drier for our western mountains though
some isolated high based showers and thunderstorms will be
possible...producing mainly gusty winds and lightning.  The San Luis
Valley could see some spotty critical fire weather conditions once
again. -KT

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 316 AM MDT Tue Apr 22 2025

Models have come into better agreement through Sunday, before
diverging into next week. Active weather looks to continue
through Friday, with a return of fire weather conditions for the
weekend. By early next week, models differ in the speed and
track of an upper low across the area, with lower overall
confidence.

Wednesday night through Friday...broad southwesterly flow aloft
with multiple embedded waves will impact southern Colorado
through Friday. Thunderstorms will likely be ongoing Wednesday
evening across the far Eastern Plains, tracking eastward into
Kansas during the overnight hours. A few may be strong to severe
during the evening hours, with hail over one inch in diameter
and winds in excess of 60 mph possible. This thunderstorm
activity looks to be east of the area by Thursday morning.

The severe thunderstorm potential on Thursday will depend highly
on a cold front. The cold front looks to wrap around a surface
low early Thursday morning, with temperatures in the upper 60s
to lower 70s for highs during the afternoon. Moisture will be in
place across the Plains, with 40s to near 50 dewpoints. 0-6km
bulk shear looks to be around 35 kts, and SBCAPE values near
1500 j/kg...all sufficient for a few strong to severe storms
Thursday afternoon across the Plains. The high-res RRFS guidance
generates an area of stronger storms late in the day Thursday,
and tracks it east into Kansas by 2 AM Friday morning. The GFS
and NAM are less bullish with convection, and further north,
keeping most activity north of Highway 50. We will continue to
monitor trends in guidance.

Low level flow will remain easterly on Friday helping to keep
moisture pooled across the Plains. Another upper wave embedded
in the southwest flow will help generate another round of
thunderstorms Friday afternoon evening. Focus looks to move to
the Eastern Mountains, and then east across the Plains during
the evening and overnight hours. A few storms could become
strong with hail and strong winds all possible. Temperatures on
Friday will continue to cool, with mainly 60s across the region.

Spotty fire weather conditions will remain possible Thursday and
Friday across the San Luis Valley due to gusty winds and low
humidity values. The most widespread and critical conditions
during this period looks to be Friday afternoon.

Saturday and Sunday...an upper low is forecast to strengthen
across California and Nevada over the weekend. Drier air will
spread eastward, forcing the low level moisture east into
Kansas. Model guidance is hinting that the dryline may mix out
to the Kansas border Saturday afternoon, and could provide the
focus for a few storms Saturday afternoon and evening. If the
dryline mixes too far east, shower and thunderstorm activity
will be off to the east in Kansas. Elevated fire weather
conditions will spread eastward from the San Luis Valley, into
the I-25 corridor Saturday afternoon. Temperatures begin to
rebound back through the 70s and into the lower 80s.

By Sunday, increasing southwesterly flow will continue across
Colorado. Widespread winds 30 to 40 mph are likely, and humidity
values will fall under 10 percent across the region. High fire
danger is likely on Sunday afternoon and evening. High
temperatures will continue to warm with upper 70s to mid 80s
across the region.

Monday and Tuesday...models differ on how they want to handle
the upper low. The GFS brings a couple of waves across, one
Monday and the main low Tuesday. The GFS would keep elevated
fire weather conditions into early next week, with increased
shower over the higher terrain. The ECMWF, ICON, and Canadian
solutions are bringing a single low across Colorado, but differ
on timing. The ECMWF and ICON track it across Colorado Monday,
with baggy troughing overhead Tuesday. The Canadian hangs the
upper low back until Tuesday. For now, followed the NBM guidance
with low pops and cooling temperatures into early next week.
Mozley

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 508 AM MDT Tue Apr 22 2025

VFR conditions at all three terminals (KALS, KCOS, KPUB) through
the next 24 hours. A few wind gusts near 20 kts will be possible
at KALS and KCOS this afternoon. Mid and high level clouds will
move across the region this afternoon and overnight.  Mozley

&&

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

&&

$$

SHORT TERM...KT
LONG TERM...MOZLEY
AVIATION...MOZLEY