308
ACUS02 KWNS 141723
SWODY2
SPC AC 141722

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1222 PM CDT Sat Sep 14 2024

Valid 151200Z - 161200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE
CENTRAL HIGH PLAINS...

...SUMMARY...
Isolated strong to severe thunderstorms are possible Sunday
afternoon and evening across parts of the central High Plains.

...Synopsis...
An upper-level trough currently residing over the northeastern
Pacific is forecast to deepen substantially over the next 48 hours
along the West Coast. This will establish a broad swath of
strengthening south/southwesterly flow across the greater Great
Basin region into the central/northern Rockies. Low-level moisture
return into the central Plains should increase as a lee surface
trough slowly deepens in response to the evolving upper-level
pattern. The increasing moisture/buoyancy quality may support some
intensification of convection as it migrates out of the central
Rockies and into the High Plains Sunday afternoon and evening.

...Central High Plains...
High-based convection is expected to develop within the central
Rockies by mid/late afternoon Sunday as a combination of deep-layer
ascent and diurnal warming steepen lapse rates. Isolated
thunderstorms are also possible in the vicinity of a deepening
surface trough across eastern WY/northeast CO where surface pressure
falls are currently expected to be strongest. Forecast guidance
suggests that this activity will intensify as it migrates northeast
and impinges on the western periphery of the moisture reservoir to
the east of the surface trough where MLCAPE values may be as high as
1000-2000 J/kg. While the central High Plains will likely remain
displaced from the strongest mid/upper-level flow, 25-30 knot
mid-level winds with modest low-level flow should provide sufficient
deep-layer shear to support some degree of storm organization with
an attendant large hail threat. Additionally, boundary-layer mixing
on the edge of the deeper moisture will be adequately deep
(mixed-layer LCLs near 2.5 km AGL) to support strong to severe gusts
with the more organized cells and/or clusters.

...Great Basin/Four Corners...
Increasing broad scale ascent over the Great Basin and Four Corners
region should result in isolated to scattered thunderstorm
development by late afternoon. While some degree of moisture return
is anticipated from the Gulf of California across southern AZ, most
regions will remain fairly warm and dry in the low-levels.  Such
thermodynamic conditions will be conducive for dry downbursts that
may be capable of very localized strong to severe gusts. The
predictability of where such gusts are most likely across the
broader region remains too limited to warrant risk probabilities.

..Moore.. 09/14/2024

$$