ACUS48 KWNS 210813

SWOD48

SPC AC 210811



Day 4-8 Convective Outlook  

NWS Storm Prediction Center Norman OK

0311 AM CDT Sun Jun 21 2026



Valid 241200Z - 291200Z



...DISCUSSION...

...D4/Wednesday and D5/Thursday - Central High Plains...

As high pressure builds into the central/northern Plains on

Wednesday and Thursday, upslope flow will remain persistent across

eastern Colorado and eastern Wyoming. Moderate to strong instability

is expected in this area with 40 to 50 knots of west-northwesterly

flow aloft. This should result in a favorable upslope regime capable

of supercells. A relatively narrow unstable corridor should keep the

most favorable severe threat somewhat confined to the higher

elevation prairies where instability and upslope flow will be

maximized. 



Friday and Saturday, ridging is forecast to translate east across

the Plains, which may lead to a relative lull in severe weather

threat. However, by Sunday and into early next week, there is a

strong signal for troughing and moderate to strong mid-level flow

across the northern Plains and into the Upper Midwest. Several days

of substantial severe weather are possible during this period.

However, at this time, the timing and amplitude of these features

make it challenging to highlight specific areas. As the evolution of

this mid-level pattern becomes more clear, severe weather

probabilities may be added in later outlooks.



..Bentley.. 06/21/2026