781
FXUS65 KPUB 100959
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
359 AM MDT Sat Aug 10 2024

.KEY MESSAGES...

- Showers and thunderstorms are expected again for our Saturday,
  some of which could be strong to severe on our plains.

- Daily showers and thunderstorms expected over the Mountains.

- Warming conditions on the Plains, back to near normal.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 339 AM MDT Sat Aug 10 2024

Currently..

Scattered to numerous showers are still making their way across the
southern half of our forecast area early this morning, though
lightning has mostly come to an end as of 3am. Widespread low and
mid-level cloud cover is blanketing the area, keeping temperatures
mostly uniform. Plains locations are in the mid 50s, with higher
terrain locations in the 40s. Dewpoints are very near ambient
temperatures across the board as many locations are either still
seeing rain or are still very near saturation. Winds are still
easterly across the plains, leading to low-level upslope conditions
for much of the I-25 corridor.

Today and Tonight..

With the high shunted off to our south, and increasing west-
northwesterly flow aloft over our region, today will be a fair bit
warmer than where we`ve been the past couple of days. Highs look to
top out in the mid 70s to mid 80s across the plains, with mid 70s
for mountain valleys and 60s for higher terrain locations. Continued
low-level moist upslope and westerly flow aloft will lead to better
shear for today, which will help to keep storms more organized this
afternoon, especially as they push off of the mountains. Instability
will also be slightly more favorable for severe development today,
though most high res model guidance still only suggests 1000 to 1200
J/Kg or so of CAPE at the most. Current thinking is that main mode
of severe will be excessive rainfall and flash flooding, especially
given how much rain many locations have received over the past 48
hours, though it does seem possible that a few stronger storms could
produce hail to 1 inch and 60 mph winds as well given the better
shear environment. The risk for flash flooding will exist with any
storms across the area, to include storms over the high country, but
the risk for hail and damaging winds will increase mainly along and
east of the I-25 corridor. Though storms look to lose their punch
quickly after sunset, isolated to scattered weaker storms and
showers look to persist into the evening and overnight hours for
many locations. Overnight lows will cool to near normal temperatures
for most, though any early clearing could mean more efficient
cooling and slightly cooler than currently forecast temperatures.
&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 339 AM MDT Sat Aug 10 2024

Models in decent agreement through Wednesday, with differences
showing up for later in the extended period. The ECMWF has
remained the most consistent from last night, with a stronger
high pressure across the region, while the GFS now takes a
Pacific Northwest low across the Northern Plains.

Sunday into Monday...flat upper ridging will prevail across the
Desert Southwest, with zonal westerly flow across Colorado. Two
embedded waves in the zonal flow are forecast to track across
southern Colorado, one on Sunday and another on Monday. Both
will allow for shower and thunderstorm development across the
region. Initiation should take place over the Mountains, and the
westerly flow aloft should help push shower and thunderstorm
activity east into the Plains during the evening hours. PWAT
values remain near 1 inch across the Plains, and SBCAPE values
near 500 to 800 j/kg will support potentially heavy rainfall.
Low level moisture will remain pooled across the Plains, and any
upslope flow will likely depend on any outflow boundaries from
previous convection. Temperatures look to warm up as well, with
80s to lower 90s for the lower elevations. Temperatures do have
potential to be cooler, and will depend on any cloud cover that
may be present. Overall, the main risks from thunderstorms will
be gusty outflow winds near 40 mph, lightning and locally heavy
rainfall that could lead to localized flash flooding on area
burn scars and flood prone areas.

Tuesday and Wednesday...both the GFS and ECMWF develop an upper
low over the Pacific Northwest for mid week, which looks to
force the upper ridge into the Central Plains. This will force
southwesterly flow across Colorado. Model guidance has most
shower and thunderstorm activity developing across the
Mountains, then spreading northeast into the Palmer Divide and
into northeast Colorado during the evening and overnight period.
Highest precipitation chances on the Plains look to be north of
Highway 50 both days. Again, locally heavy rainfall, lightning
and gusty outflow winds will be the main concerns. Temperatures
will continue to be warm with the lower elevations seeing highs
in the 80s to lower 90s.

Thursday into Saturday...pretty big differences between the
model guidance for late week. The ECMWF weakens the upper low
over the Pacific Northwest, allowing the upper high to
strengthen across Colorado. Shower and thunderstorm activity
would look to be confined to the higher elevations with less
coverage. Temperatures would also be a bit warmer than the
current forecast temperatures. The GFS is more progressive with
the upper low, tracking it east across Montana and into the
Northern Plains by late week. The GFS keeps northwesterly flow
across Colorado, with the upper high building further west. This
would also keep better chances for showers and thunderstorms
across the Plains, along with possibly cooler temperatures.
Given the uncertainty in the forecast, did not stray from the
NBM guidance, with near seasonal temperatures and continued
precipitation chances for most of the region.  Mozley

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 339 AM MDT Sat Aug 10 2024

For KCOS and KPUB..IFR and LIFR ceilings and visibilities in mist
will continue to be possible through the early morning hours, with
clearing expected after 13Z. Conditions improve to VFR through the
late morning hours, before more chances for showers and
thunderstorms move in after 21Z at both stations.

For KALS..Light showers and MVFR ceilings are expected off and on
over the next few hours, with clearing beginning after 14Z. Chances
for showers and thunderstorms move back in after 18Z tomorrow,
though confidence in thunder over or near station was too low to
include in the TAF at this time.

&&

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

&&

$$

SHORT TERM...EHR
LONG TERM...MOZLEY
AVIATION...EHR