959
ACUS48 KWNS 120901
SWOD48
SPC AC 120900

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Wed Jun 12 2024

Valid 151200Z - 201200Z

...DISCUSSION...
...Saturday/Day 4 to Saturday/Day 5...
On Saturday, an upper-level trough is forecast to move northeastward
across the southern and central High Plains. An axis of instability
is forecast to be further to the northwest across the western
Dakotas. As a mid-level jet passes northeastward across the northern
Rockies, large-scale ascent and deep-layer shear should be strong
enough for an isolated severe thunderstorms in parts of the northern
High Plains. Large hail and severe wind gusts will be possible, but
uncertainty exists concerning the spatial distribution of the
threat.

The trough in the central Plains is forecast to move into the upper
Mississippi Valley on Sunday, with a large pocket of instability
located in its wake across the central Plains. Although large-scale
ascent within this unstable airmass is expected to be weak, isolated
severe storms could develop in the late afternoon and early evening.


Further to the northwest, model forecasts show potential for storm
development in parts of the northern High Plains Sunday evening. If
this were to occur, MCS development, and an isolated severe threat,
could occur across parts of the northern Plains Sunday night.

...Monday/Day 6 to Wednesday/Day 8...
On Monday, a mid-level jet is forecast to move northeastward into
the northern Plains, as a moist and unstable airmass remains in
place across the Upper Midwest. Severe thunderstorms may develop
across parts of the region during the afternoon and evening, in
association with any shortwave trough that can translate through the
flow. The models suggest there is enough potential on Monday for a
more widespread severe threat, to add a 15 percent contour in parts
of the eastern Dakotas and Minnesota.

On Tuesday, an upper-level trough is forecast to move across the
northern Plains. Isolated strong to severe thunderstorms would be
possible ahead of the trough in parts of the upper Mississippi
Valley. As the trough moves through southeastern Canada on
Wednesday, severe storms would be possible in parts of the
Northeast. However, uncertainty is considerable at this range in the
forecast period.

..Broyles.. 06/12/2024