923
FXUS65 KPUB 292124
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
324 PM MDT Sat Jun 29 2024

.KEY MESSAGES...

- Thunderstorm chances increase this evening/tonight, along
  with the risk for severe storms and heavy rainfall with flash
  flooding. Flash Flood Watch in effect for the far southeast
  plains.

- Thunderstorm chances along with the risk of severe storms and
  heavy rainfall with flash flooding return on Sunday.

- Thunderstorms decrease in coverage and intensity for the
  Monday through Wednesday timeframe.

- Dry conditions return for Fourth of July, which will mean
  less thunderstorm coverage for many, but marginal fire danger
  for some.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 322 PM MDT Sat Jun 29 2024

Relatively quiet this afternoon, with latest radar imagery
showing only isolated shower and thunderstorm development across
primarily the Continental Divide. Meanwhile, post frontal air
and early morning cloud cover has supported relatively cooler
temperatures this afternoon. For the remainder of the afternoon,
expect isolated to widely scattered showers and thunderstorms
to continue over and near the higher terrain, where slightly
better moisture and instability reside. While can`t rule out an
isolated stronger storm this afternoon and potentially a severe
storm, think this risk is low given overall low values of
moisture and instability. If a stronger storm or even severe
storm were to occur, think wind gusts up to 60 mph would be the
main risk.

By this evening, will see the mid level energy which is moving
overhead right now, continue to push across the region. This
will support lee troughing in the lower and mid levels this
evening. Higher moisture along with higher instability, that is
to the southeast, finally returns in this setup. Will likely see
the risk of scattered strong to severe storms spread into the
I-25 corridor, with hail to the size of quarters and wind gusts
up to 60 possible with any severe storm. This risk looks to
continue through mid evening, and possibly shifting to the east
of the I-25 corridor but attention quickly turns to the far
southeast plains by mid to late evening. In this area,
instability and moisture will be the highest with CAPE values of
1000-2000 j/kg in place, surface dew points in the low to mid
60s, and PWATs approaching 1.75 to 2.00 inches. Additionally,
bulk shear with be in the 40-50 range. This is concerning
because focus for ascent really ramps up during this time across
the far southeast plains. Will see the lingering boundary and
surface trough in place, as southerly 700mb flow ramps up over
head. This increase in likely persistent focus/forcing will
support an increasing risk for severe storms with hail up to
1.50 inches in diameter and wind gusts up to around 60 mph
possible. Additionally, given the setup and potential for
training thunderstorms, have issued a Flash Flood Watch for the
far southern tier of counties across the far southeast plains.
While forecast amounts are in the 1- 3 inch range, locally
higher, some model raw output is showing localize amounts up to
around 5 inches. Once again, the moisture, instability, and
setup could support these higher amounts. Will need to monitor
for a slight shift north in the development with time during the
over night hours, and the possibility of expanding the Flash
Flood Watch. Showers and thunderstorms will likely continue for
most of the night, but should see the severe risk lessen during
the overnight into the early morning hours as instability
diminishes.

General drying trend is expected through the morning hours on
Sunday, though some lingering showers may persist across the far
southeast plains as well as a few showers and thunderstorms
over the southwest mountains. Ridge in place on Sunday, though
will see a continued stream of mid level energy along with
additional lee troughing. While this is expected, there is some
uncertainty as to where this will occur. This will not only
factor on focus for thunderstorm development, but will play into
the extent of the westward movement of the higher moisture and
instability. Given some likely steady east/southeast flow at
the surface dew points could easily exceed 60 degrees across the
plains, while CAPE meets or exceeds 2000 j/kg and while bulk
shear increases. Will need to monitor where this sets up and
once again, how likely capping in place will factor into
development. Nonetheless, a severe risk is in place on Sunday,
with all hazards possible. Meanwhile, will see increasing
moisture and focus across the Continental Divide that will
likely support periodic shower and thunderstorm development.
Can`t rule out a strong to severe storm, but think the risk of
heavy rainfall and possible flash flooding will be the main
threat.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 322 PM MDT Sat Jun 29 2024

For Monday and Tuesday, we will see warming and drying, as a
trough tries to pass to our north and our flow aloft remains
weak and southwesterly. This will keep afternoon and evening
showers and thunderstorms in our forecast, especially over and
near the mountains, though coverage and intensity will decrease
from this weekend`s activity. Temperatures both days will be
just a few degrees above normal for most locations, and critical
fire weather looks to be unlikely due to weak winds, though we
will be fairly dry by Tuesday with humidity values falling down
into the 17-22% range over portions of the Arkansas River Valley
that afternoon. Models bring a cold front across the plains
Tuesday night, which will cool things off for our Wednesday,
leading to increased rain and thunderstorm chances for much of
the area, along with near or just below normal temperatures for
many locations.

Fourth of July and Onwards..

Ensembles bring quieter and more northwesterly flow aloft
towards our region by Thursday behind the passing trough to our
north, which should lead to at least a day or two of very sparse
thunderstorm chances, and warmer temperatures for Thursday and
Friday. One concern with our Fourth of July forecast is that our
relative humidity values look to fall down into the low to mid
teens in a few places, including the upper and middle Arkansas
River Valley to include the Pueblo area, along with northern
Teller County, which could lead to dangerously dry conditions
for Holiday activities. For most areas, winds look to remain
below critical fire weather thresholds, but the overall dryness
could end up being something that needs to be monitored as the
Holiday approaches. Models bring a cold front across our plains
sometime in the Thursday night or Friday morning timeframe,
which should help to increase our humidity values and decrease
our temperatures for Friday and Saturday, but will also increase
our chances for showers and thunderstorms for both days as
well.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1135 AM MDT Sat Jun 29 2024

For KCOS and KPUB..VFR conditions are expected for the next few
hours early this afternoon, before showers and thunderstorms begin
to push off the terrain and near or over both stations after 23Z
this afternoon. MVFR conditions during thunderstorms will be
possible, along with gusty and erratic thunderstorm winds from
around 00Z through 06Z this evening. MVFR and IFR ceilings and
visibilities are also expected from 06Z through around 14-16Z
tomorrow morning due to stratus and upslope conditions, and could
persist longer at KCOS.

For KALS..VFR conditions are expected for the next 24 hours, with a
slight chance for vicinity showers and weak thunderstorms this
afternoon, mainly from 23Z until 03Z. Winds are expected to be
mostly light today, but could be gusty and variable near
thunderstorm activity later this evening.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for COZ088-094-099.

&&

$$

SHORT TERM...RODRIGUEZ
LONG TERM...EHR
AVIATION...EHR