611
ACUS48 KWNS 170827
SWOD48
SPC AC 170825

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0325 AM CDT Wed Jul 17 2024

Valid 201200Z - 251200Z

...DISCUSSION...
Extensive upper ridging is expected to extend from the Southwest
into western Canada on D4/Saturday morning. This upper ridging is
forecast to persist throughout the weekend and into early next week,
shifting gradually westward during this period. Modest downstream
upper troughing across the central and eastern CONUS is expected to
persist through the weekend and into next week as well, with some
westward shift of this troughing also possible. In general, no
substantial changes to the upper pattern are currently anticipated
from D4/Saturday to D8/Wednesday.

Moderate northwesterly flow aloft is expected between these two
features, extending across the northern and central High Plains on
D4/Saturday before then shifting westward. Current guidance suggests
a low-amplitude, convectively augmented shortwave trough may move
through this northwesterly flow across central Plains.
Predictability of these types of shortwaves is low at this forecast
range, but it would provide the lift needed for storm development if
realized. Lift attendant to this shortwave and/or low-level
convergence along the lee trough could support thunderstorms across
the northern and central High Plains and adjacent Plains. Modest
low-level moisture beneath vertically veering wind profiles could
result in some strong to severe thunderstorms.

The severe risk is expected to be lower from D5/Sunday into
D8/Wednesday, as the northwesterly flow aloft shifts westward and
weak upper flow prevails across much of the central and eastern
CONUS.

..Mosier.. 07/17/2024