399
ACUS48 KWNS 210856
SWOD48
SPC AC 210854

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0354 AM CDT Fri Aug 21 2026

Valid 241200Z - 291200Z

...DISCUSSION...
A mid-level trough will move across the Northeast on Monday and the
surface front will be mostly offshore, reducing the severe weather
threat. As this trough departs, ridging will build across the
Rockies. This will eventually set up a pattern featuring individual
mid-level shortwave troughs within northwesterly flow from the
northern Plains to the Midwest. Some severe weather will likely
occur with mid-level shortwave troughs within this flow, but these
details likely will not become more clear until the short term.

Model consensus indicates a stronger mid-level shortwave trough
traversing the Pacific Northwest on D7/Thursday. This pattern would
be favorable for some severe weather threat across Montana, but at
this time, it appears moisture will stay farther east. Therefore, no
severe weather is anticipated.

..Bentley.. 08/21/2026