255
ACUS48 KWNS 260840
SWOD48
SPC AC 260838

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0338 AM CDT Wed Jun 26 2024

Valid 291200Z - 041200Z

...DISCUSSION...
...D4/Saturday: Central/southern Plains into the Midwest/OH
Valley/Northeast...
A mid/upper-level trough is forecast to move from the upper Great
Lakes across parts of Ontario and Quebec on D4/Saturday, in
conjunction with a surface cyclone. A belt of relatively strong
mid/upper-level flow will move eastward along the southern periphery
of this trough. The extent to which the stronger flow overlaps the
warm sector of the cyclone is somewhat uncertain, but a corridor of
organized severe-thunderstorm potential could evolve across parts of
the Midwest/OH Valley into parts of the Northeast.

Farther southwest, a cold front moving across the Ozarks vicinity
and central/southern Plains will tend to be displaced from stronger
flow aloft. However, potentially strong instability could support
some severe threat in association with the front from parts of
southern KS and OK into northern AR and southern MO.

...D5/Sunday: Mid Atlantic into the Northeast...
Timing of the cold front that moves across parts of the Great Lakes
on Saturday becomes increasingly uncertain by Sunday. However, a
slower frontal progression would allow development of strong to
potentially severe thunderstorms from parts of the Mid Atlantic into
the Northeast.

...D5/Sunday: Central/northern High Plains...
A mid/upper-level trough is generally forecast to move from the
Northwest across the northern Rockies on Sunday. Some low-level
moisture return is expected to the east of a developing surface low
across WY/MT. Depending on the timing of the trough and magnitude of
moisture return, strong to severe thunderstorms will be possible
across parts of the northern/central High Plains Sunday
afternoon/evening.

...D6/Monday into D7/Tuesday: Parts of the central/northern Great
Plains into the Midwest...
The mid/upper-level trough that moves across the northern Rockies on
Sunday is forecast to continue eastward into the northern/central
Great Plains on Monday, as a surface low moves northeastward across
the Dakotas in conjunction with a warm front. The corridor of
favorable instability may be relatively confined due to the
influence of a surface ridge covering much of the eastern CONUS, but
some severe-thunderstorm potential could evolve from parts of the
Dakotas southward into KS/NE, and potentially farther east into
MN/IA/MO.

Depending on the extent of moisture return and destabilization, some
severe potential could spread into a larger part of the Midwest on
D7/Tuesday, as the mid/upper-level trough continues eastward.

..Dean.. 06/26/2024