178
FXUS65 KPUB 131733
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1133 AM MDT Tue Aug 13 2024

.KEY MESSAGES...

- Thunderstorms with heavy rainfall once again possible this
  afternoon and evening.

- A few strong storms possible east of I-25 and north of
  Highway 50 this afternoon and evening.

- Mainly isolated showers and thunderstorms Wednesday through
  Monday, with the greatest coverage over and near the
  mountains.

- Near to slightly below seasonal temperatures expected
  Wednesday and Thursday, with a warm up to above seasonal
  temperatures for Friday through Monday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 341 AM MDT Tue Aug 13 2024

Currently...satellite imagery early this morning shows an upper
ridge axis shifting east across Colorado with increasing
southwesterly flow spreading across western portions of the state.
Continued embedded energy is producing light rain with isolated
thunder along the Continental Divide, east into the San Luis Valley
this morning.  Expect this activity shift northeast this morning,
dissipating by daybreak as it does so.  Temperatures remain mild
across the Plains with mostly 60s.  Moisture remains pooled across
the Plains as well, with dewpoints in the upper 50s to mid 60s.

Today...the upper ridge axis will continue shift eastward into the
Central Plains by this afternoon.  Southwesterly flow is forecast to
spread eastward behind the departing upper ridge.  Models in good
agreement with a strong embedded vort max, forecast to move from
near the Four Corners this morning, northeast into northeast
Colorado by this evening.  Expect showers and thunderstorms to
develop by mid morning across the higher terrain.  This activity
will then spread northeast into the Palmer Divide by this afternoon
as the upper vort max lifts across the area.  Given the upper flow
pattern, areas from the Continental Divide, northeast into the
Palmer Divide, and north of Highway 50 will see the best chances for
thunderstorms with heavy precipitation.  PWAT values remain high
over the Plains at near 1.5 inches.  SBCAPE values over 1000 j/kg
will exist across the Plains, however, 0-6 km shear is on the weaker
side at 25 to 30 kts.  Better conditions look to exist across
northeast Colorado.  That being said, there is a marginal risk for
severe storms, mainly east of I-25, and along and north of Highway
50 across the Plains.  All storms today will be capable of heavy
rainfall with localized flash flooding on area burn scars and flood
prone areas.  Stronger storms on the Plains may produce hail to near
1 inch in diameter and wind gusts near 60 mph.  South of Highway 50,
showers and thunderstorms look to be more limited in coverage, and
likely will depend on convection that roles of the higher terrain
into the southern I-25 corridor this afternoon.  Temperatures this
afternoon will warm back through the 80s to mid 90s across the lower
elevations, with 70s across the San Luis Valley.

Tonight...the upper vort max will move from northeast Colorado into
Nebraska overnight.  Showers and thunderstorms will track northeast
from the Palmer Divide, across northeast Colorado, and into Nebraska
and Kansas overnight.  The overall severe threat should diminish
around sunset with loss of daytime heating.  But areas of locally
heavy rainfall will remain possible, especially for areas along and
north of Highway 50 through around midnight.  Subsidence behind the
departing upper vort max will help clear out southern Colorado by
Wednesday morning.  As flow turns northwesterly, a few light showers
and isolated thunder may be possible through the overnight hours
along the Continental Divide.  Temperatures look to be slightly
cooler overnight with upper 50s to mid 60s across the Plains.
Mozley

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 341 AM MDT Tue Aug 13 2024

Wednesday: The midweek period will bring some active weather to
south central and southeastern Colorado. A shortwave trough will be
pushing over the region throughout the day. While this feature will
bring heightened lift to the area, it will also start to scour out
the moisture that has been in place. Given this, afternoon rain
showers and thunderstorms are anticipated, though will be more
isolated to scattered in nature, and remain mostly along and
immediately around the mountains, where forcing will be greatest.
While no severe weather is expected, a strong storm or two, capable
of producing strong winds and small hail, will be possible given
modest shear and instability in place. With that all said, any
showers and storms present during the day will dissipate during the
evening hours as instability wanes. As for temperatures, a near
seasonal day is anticipated. However though, cool outflows from the
afternoon showers and storms may help to cool some places for the
afternoon. In addition, a cold front will push southward Wednesday
night, bringing cooler temperatures for Thursday.

Thursday - Monday: For the rest of the long term period, a
relatively quieter start will transition into an uptick in activity
for the weekend and start of next week. A ridge will slowly start to
redevelop behind the exiting shortwave trough from Wednesday. For
Thursday and Friday, drier air will remain in place after better
moisture was scoured out Wednesday. Given this, much of the area
will remain dry, though isolated rain showers and thunderstorms
will remain possible along and immediately around the mountains each
afternoon. Then for Saturday through Monday, the ridge is expected
to continue to expand and moisture is expected to start increasing
over the region. Though no major forcing is anticipated, orographic
and diurnal forcing, coupled with the uptick in moisture, will allow
for showers and storms to expand in coverage again, with the
greatest coverage around the Continental Divide area. Gusty
winds, heavy rain, and lightning will be possible with any more
organized thunderstorms. Like a typical Summer pattern though,
any showers and storms present during the afternoon will start
to dissipate during the evening hours as instability lessens.
Looking at temperatures, Thursday will be the coolest day thanks
to the cold front passage late Wednesday night, keeping
temperatures at or slightly below seasonal values. Beyond
Thursday, a slow warmup is expected as the ridge rebuilds. Much
of the region will start to warm to above seasonal temperatures
for mid August.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1123 AM MDT Tue Aug 13 2024

At KALS, vcts 20z-02z, with erratic/gusty winds the main storm
hazard. VFR overnight into Wed, with only very isolated
convection expected Wed afternoon.

At KPUB and KCOS, vcts at both sites 21z-03z, with tempo tsra
and a brief period of MVFR vis possible as stronger storms move
through 22z-02z. VFR overnight with convective debris clouds
slowly diminishing into Wed morning. Lesser chance for
convection Wed afternoon as air mass begins to dry out.

&&

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

&&

$$

SHORT TERM...MOZLEY
LONG TERM...SIMCOE
AVIATION...PETERSEN