109
ACUS48 KWNS 090901
SWOD48
SPC AC 090900

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Sun Jun 09 2024

Valid 121200Z - 171200Z

...DISCUSSION...
...Wednesday/Day 4 and Thursday/Day 5...
A low amplitude shortwave ridge is forecast to move across the
northern Plains on Wednesday, where a moist and unstable airmass
will likely be in place. Scattered thunderstorms will be possible
Wednesday afternoon across parts of this airmass from eastern South
Dakota and southwestern Minnesota southward into the mid Missouri
Valley. The medium-range models are in reasonable agreement, with
moderate deep-layer shear in place across much of the region. This
would be favorable for organized storms, with a severe threat
possible during the late afternoon and early evening.

On Thursday, a cold front is forecast to move southward into the mid
Missouri and mid Mississippi Valleys. A moist and unstable airmass
is forecast to the south of the front. Most models develop moderate
instability near and to the south of the front by afternoon, and
show potential for convective development. Model forecasts suggest
that moderate deep-layer shear will be in place across much of the
moist airmass, resulting a chance for organized thunderstorms from
late afternoon into the evening.

...Friday/Day 6 to Sunday/Day 8...
From Friday to Sunday, an upper-level ridge is forecast to move from
the north-central U.S. into the Great Lakes, as an upper-level
trough approaches the northern Plains. Ahead of the trough, isolated
to scattered strong to severe storms will be possible each day
across the north-central U.S. Based on the latest runs, the greatest
potential for severe would be on Sunday in the northern Plains, as
the upper-level trough approaches. However, model spread is large
during this three day time span, suggesting that severe threat
predictability is low.

..Broyles.. 06/09/2024