640
FXUS65 KPUB 200711
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
111 AM MDT Sat Jul 20 2024

.KEY MESSAGES...

- Strong to severe thunderstorms possible through this evening
  across the eastern plains.

- Another round of thunderstorms expected for Saturday though severe
  potential looks lower due to less shear.

- Unseasonably cool and unsettled this weekend into early next week.

- Some drying, especially across southeast Colorado, for the
  middle to end of next week, with temperatures warming back to
  near seasonal levels.

&&

.UPDATE...
Issued at 105 AM MDT Sat Jul 20 2024

Updated to adjust pops across the Plains through around 3 AM as
a frontal boundary pushes south. Isolated to scattered showers
and thunderstorms continue along the boundary and will do so
until the boundary clear south into New Mexico around 3 to 4 AM.
Mozley

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 234 PM MDT Fri Jul 19 2024

Upper trough across the Dakotas will continue dropping southward
along the eastern periphery of the western U.S. upper high through
the central plains this evening.  Meanwhile, recycled monsoon
moisture continues to circulate within the upper high over CO.  The
former feature is sending a cold front through the southeast plains
with storms firing along this boundary across southern El Paso
county as of 20z.  Dew points to the north of the boundary in El
Paso county have dropped off into the 40s and even upper 30s, while
south of the boundary dew points remain in the 50s to around 60
across the far southeast plains. High res models continue to portray
a line of storms becoming more organized across northeast CO/western
KS dropping southward through the far eastern plains during the late
afternoon and evening with the frontal boundary acting as the
primary initial focus, then a secondary wave possible after 7 PM.
Details are murky on the coverage and westward extent of stronger
thunderstorms, but with upper 50s/lower 60 dew points maintaining
across Kiowa, Bent, Prowers and Baca counties, this is where the
higher CAPE is likely to linger with up to 1500 J/kg or a little
better of MLCape.  Deep layer shears will be running around 30-35
kts. As storms organize into linear cluster/MCS the storm risks will
transition more towards damaging winds near the CO/KS border through
the evening.

Meanwhile, over the mountains and adjacent plains storms will be
higher based as low level moisture mixes out some vs that of
previous days.  A heavy rain risk will be maintained as precipitable
waters remain around 100-115% of normal.  Burn scar flash flooding
will be possible if storms impact these areas, otherwise gusty
outflows up to 50 mph and some small hail will be possible with the
embedded stronger cells.

Front pushes through all of the southeast plains tonight with winds
shifting around from the east on Saturday.  Temperatures will be
cooler on Saturday with readings staying in the 80s for most areas
across the plains, 70s to around 80 for the mountain valleys and 50s
and 60s for the higher terrain.  Thunderstorms will increase across
the mountains again Saturday afternoon as weak perturbations
continue to circulate within the upper high.  Forcing looks weak
compared to today, but afternoon heating should be sufficient for
fairly widespread shower and thunderstorm activity once again. Mean
Cape off HREF ranges from 500 to near 1000 J/kg however weaker deep
layer shears under 30 kts should limit the overall severe threat.
Still enough instability to suggest some small hail, and gusty winds
up to 50 mph along with locally heavy rainfall.  Burn scars will
need to be monitored closely for a flash flood risk. -KT

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 234 PM MDT Fri Jul 19 2024

Latest ensemble and operational model data continues to support a
cool and unsettled pattern across the region through Monday, as
upper level ridging elongates across the Great Basin and
Intermountain West, keeping unseasonably cool north to northwest
flow aloft across the Rockies. With moisture in place (PWATS
between 100-150 percent of normal), and bouts of increased uvv
with embedded waves translating down the backside of the upper
ridge across the Northern Rockies and into the High Plains, we
will continue to see daily chances of showers and thunderstorms,
with the best coverage over and near the higher terrain, this
weekend into early next week. With the cooler conditions, models
indicate less instability with severe storm development being
limited, however, with the available moisture in place and the
potential for training storms, locally heavy rainfall and
localized flash flooding will be possible through the weekend.
A few models continue to suggest a cold front, pushing south
across Eastern Colorado Saturday night, could develop showers
and storms across the region early Sunday morning, which could
continue through the afternoon and evening. With the easterly
low level upslope flow, Sunday remains to be the coolest days of
the next week with highs well below late July levels in the 70s
to lower 80s across the Plains, with 50s, 60s to lower 70s
expected across the higher terrain.

For Tuesday and beyond, model data continues to suggest the upper
high will slowly slide south and east through the middle of
next week and could be sliding into western Colorado by the end
of next week. This will shift upper level flow to east to
northeast across Eastern Colorado, with weak southerly flow
developing across Western Colorado. The main weather signal is
slowly warming conditions across the region with temperatures
returning at to slightly above seasonal levels by the end of
next week. Drier conditions look to develop across Eastern
Colorado, while Western Colorado could see a slow increase in
available moisture once again, keeping the best chances of daily
storms along and west of the ContDvd for the end of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1112 PM MDT Fri Jul 19 2024

VCSH to continue for KCOS and KPUB for a couple more hours
tonight with potential gusty and erratic outflow across the
eastern plains. Otherwise, VFR conditions over the next 24 hrs
for much of the forecast area, including the three main TAF
sites of KCOS, KPUB and KALS. VCSH returns to all three terminal
forecast starting 20-22z tomorrow, with the potential for
intermittent MVFR conditions due to lowering clouds and vsby
from brief periods of heavier rain.

&&

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

&&

$$

UPDATE...MOZLEY
SHORT TERM...KT
LONG TERM...MW
AVIATION...MOORE