416
FXUS65 KPUB 191727
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1127 AM MDT Sun May 19 2024

.KEY MESSAGES...

- Warm, dry, and windy conditions expected today, with a medium
  chance (40-59%) for isolated thunderstorms, a few severe,
  across the eastern plains this afternoon.

- A few storms will develop during the afternoon on Monday,
  mainly north of Highway 50, with the highest probability being
  over the Palmer Divide.

- Critical fire weather conditions will be possible for the
  lower elevations of the Sangres and within the Wet Mountain
  Valley on Monday from afternoon through early evening.

- A frontal boundary will be pushing through Monday night,
  which will usher in some cooler temps for Tuesday and
  Wednesday.

- There will be an uptick in thunderstorm activity on Tuesday
  with some high elevation snow, followed by an overall drier
  pattern for SE Colorado from Wednesday through Saturday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 430 AM MDT Sun May 19 2024

Upper trough is situated across the western CONUS at this time, with
southwesterly flow in place across the region. In this setup, a
steady stream of mid/upper level moisture is currently moving across
southern Colorado, with this resulting in mainly mid clouds passing
overhead. Radar trends have noted weak returns early this morning,
but don`t think much is reaching the surface given some drier air in
place. That being said, can`t rule out a sprinkle or two early this
morning, before these clouds clear out later this morning. Sunny
skies with additional warming will support above normal warmth
today. This warmth along with dry and windier conditions will
support critical fire weather conditions over much of southern
Colorado. As previously noted, fuels across most of southern
Colorado are not critical at this time, with fire weather headlines
not needed today.

Still keeping a close eye on isolated thunderstorm development
across mainly the far southeast plains this afternoon. Early morning
instability/moisture axis does expand back west/northwest this
morning and with daytime mixing, will see current CIN place erode.
However, with daytime mixing, will also see much drier air push east
across the plains, focusing the higher moisture and instability just
to the east in Kansas. As has been noted with previous forecasts,
there still looks to be a medium chance (40-59%) for isolated
thunderstorms to develop before this moisture/instability gets
pushed east. This development will be focused along the moisture
discontinuity, as a shortwave trough looks to push across the
region. Feel fairly confident of this possibility given recent
trends with short term and hires data, including HREF paintballs
indicating several members developing precip this afternoon. At this
time, the highest chances are from around noon through 3 PM, along
and east of a Kim to Lamar line. Given the extent of the instability
and shear, anticipate the strongest storms to be capable of
producing hail to the size of half dollars and wind gusts up to 60
mph. By mid to late afternoon, focus and instability/moisture shift
east, quickly ending the threat of severe weather.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 430 AM MDT Sun May 19 2024

Monday through Tuesday...

An approaching major shortwave trough is going to cause winds to
increase out of the southwest across the region, and especially for
the higher terrain. This will allow for lower RH values and gusty
winds to lead to fire weather conditions becoming widespread across
the lower elevations of the Sangre de Cristo Mountains (below 7500
ft) and within the Wet Mountain Valley by afternoon and continuing
into the early evening hours on Monday. Some mid-level moisture
advection, combined with orographic lifting will provide the
development of thunderstorms, mainly for the higher terrain and
areas north of Highway 50. When looking and CAM guidance, the area
that appears to have a higher probability of thunderstorms will be
over the Palmer Divide area. These thunderstorms should be more
isolated in nature and mostly confined to the mountains, although
there could be a few storms that move out over the adjacent valleys
and plains. Given how dry the lower levels with inverted V profile
reflected in the soundings, there could be some strong and gusty
outflow winds produced by the collapsing of some of these
showers/storms. Downsloping winds out of the southwest winds will
also help to adiabatically warm the lower levels, and there could be
some locations approaching the 90 degree mark for highs on Monday
across the plains.

A frontal boundary associated with this major shortwave trough will
move through by later in the night on Monday, which will allow for
winds to switch to a more northerly direction over the plains and
advect in some cooler temperatures with highs around 10 degrees
cooler from where they will be on Monday. The progression of the
wave, with an U/L low propagating to the north of the region will
help to ramp up northwesterly flow with colder air aloft and give
way to an uptick in thunderstorm activity on Tuesday, especially
over the plains by later in the evening.

Wednesday through Saturday...

The pattern is going to remain overall active, with a series of
shortwaves passing just to the north of the region and provide a few
thunderstorms over the higher terrain. Otherwise, it will be
generally drier for most areas as the southwesterly winds continue
to keep SE Colorado more dryslotted, with most of the thunderstorm
activity remaining over the northern half of the state. Temperatures
will remain right around the seasonal average for perhaps a few
degrees cooler across the mountains and yet a few degrees warmer for
the lower elevations throughout this period in the forecast as an
overall longwave trough remains in place over most of the CONUS.
Given the gusty southwesterly winds continuing over the higher
terrain, there could also be fire weather conditions possible during
the afternoon and evening hours on Wednesday and through Saturday
over the one location where fuels are still critical; elevations
below 7500 ft in the Sangres and Wet Mountain Valley.   -Stewey

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1120 AM MDT Sun May 19 2024

VFR conditions anticipated across mouch of the forecast area
over the next 24 hrs, including the three main TAF sites of
KCOS, KPUB and KALS. Southwest winds will be on the increase
this afternoon at terminal sites with gusts 22-27 kts expected
from 20z until around 02z. A few thunderstorms may develop
across the far eastern plains this afternoon near the KS border,
between 20-23z, but are expected to quickly push east-northeast
into KS.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Monday afternoon through Monday
evening for COZ225.

&&

$$

SHORT TERM...RODRIGUEZ
LONG TERM...STEWARD
AVIATION...MOORE