439
FXUS65 KPUB 202337
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
537 PM MDT Mon May 20 2024

.KEY MESSAGES...

- Showers anticipated along the mountains tonight, with dry
  conditions expected elsewhere.

- Mountains showers continue through tomorrow, with isolated to
  scattered showers possible elsewhere during the afternoon.

- Isolated to scattered showers/thunderstorms possible from Thu
  into the holiday weekend, especially across the mountains and
  Palmer Divide.

- Increase in fire danger possible Thursday as winds strengthen.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 220 PM MDT Mon May 20 2024

Tonight: Relatively quiet conditions are expected for much of south
central and southeastern Colorado Monday night. Broad troughing will
be in place, and a short wave will eject to the NE over the region
during the evening and overnight hours. Forcing will already be
heightened across the area, and this wave will help it surge during
this period. With the increased synoptic, and orographic, forcing,
showers are expected to blossom across the area, though mostly along
the mountains where forcing will be most focused. Given the
direction of flow, some showers may get pushed off of the higher
terrain and move across the valleys. Otherwise though, dry
conditions are anticipated. Along with all of that though, a dryline
will be sitting across the eastern plains during the evening hours.
While shear and instability would be supportive of organized and
severe thunderstorms, a strong and strengthening cap is expected to
stunt any convective growth, and confidence in any thunderstorm
development remains very low (<19%). If a thunderstorm were to
blossom and become mature, severe weather would be likely, with all
severe modes possible. Looking at temperatures, a relatively warm
and mild night is anticipated given downsloping westerly winds. The
plains will drop into the upper 40s to mid 40s, the valleys cooling
into the 30s, and the mountains sinking into the 20s.

Tomorrow: For Tuesday showery weather continues for portions of the
area. The broad trough will continue to be in place over south
central and southeastern Colorado, keeping the synoptic and
orographic forcing ongoing. This will allow for showers to continue
over the mountains, especially the central mountains, where forcing
will be strongest. Like Monday night, given the direction of the
flow from the southwest, some showers along the higher terrain are
expected to become shoved across the valleys during49 the day. Along
with that, a cold front will be draped across the eastern plains,
generally from El Paso County to the southeast over Prowers/Baca
Counties area. Forcing along this front, and surface upsloping
behind it, is anticipated to aid in additional isolated to scattered
rain shower and thunderstorm development during the afternoon,
though particularly along the Palmer Divide, where surface upsloping
will be greatest. Otherwise, some afternoon clouds and dry
conditions outside of afternoon showers are expected for much of the
region. As for temperatures, a cool down is anticipated given the
front and unsettled pattern overhead. The plains will rise into the
low 70s to low 80s, the valleys reaching into the mid 50s to mid
60s, and the mountains warming into the mid 30s to low 50s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 220 PM MDT Mon May 20 2024

Upper wave moves through the area Tue night, bringing scattered
showers and thunderstorms to mainly the northern half of the
area, along and north of Highway 50. Lack of instability will be
the limiting factor for heavy precip and severe storms Tue
evening, as surface CAPE is less than 500 J/KG across the
eastern plains, though strong shear (0-6km bulk shear is 70 kts)
and dynamic lift with the passing wave could contribute to some
briefly strong storms along the Palmer Divide. Any precip exits
the area by early Wed morning, with sly surface winds already
returning to the plains by Wed afternoon. Very slight chance of
some showers/thunderstorms over the ern mountains and adjacent
plains Wed afternoon as airmass becomes weakly unstable, though
deterministic models have trended drier the past few runs.
Slight mid-level cooling will knock just a couple degf off of
daytime maxes, leaving 60s/70s widespread across the region.
Thursday looks breezy/warmer/drier as low/mid level flow turn
southwesterly ahead of next upper trough sliding eastward into
the nrn Rockies. Again, best upward motion stays mainly north of
the area as wave moves into the nrn plains, with low chances
for convection Fri/Fri evening as weak post-frontal upslope
develops on the plains and some secondary energy slides across.
Temps Thu will climb to well above average levels, falling back
toward seasonal averages Fri.

Still another wave moves by to north during the weekend, and at
least a few 20/12z models hint at the possibility of stronger
convection over the area as low level moisture potentially
sloshes back west on the plains. Still a lot of mesoscale
details to go before latching onto this scenario, so stuck with
NBM pops for now, which keep precip again confined to areas
north of Highway 50 once again, but given the holiday weekend,
situation should be monitored for any increase in rainfall
chances and severe storm potential. Wrn upper ridge then appears
to amplify next week, with a slow warming trend possible, though
northwest upper flow and lingering low level moisture may lead
to some afternoon convection along and east of the mountains
Mon/Tue. Weekend/early next week temps look to say a few degf
above seasonal averages each day, though no extreme heat is
expected.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 536 PM MDT Mon May 20 2024

VFR conditions are expected at all three TAF sites, KCOS, KPUB, and
KALS for the next 24 hours. Gusty southwesterly winds will continue
for the next couple of hours, and will weaken after sunset this
evening. Breezy southwesterly winds will return tomorrow, with gusts
to 35kt at KALS. Some afternoon and evening shower and thunderstorm
activity is likely across the area tomorrow, with the highest
confidence of vicinity showers for KCOS after 21Z tomorrow
afternoon.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for COZ225.

&&

$$

SHORT TERM...SIMCOE
LONG TERM...PETERSEN
AVIATION...EHR