400
ACUS03 KWNS 160712
SWODY3
SPC AC 160711

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0211 AM CDT Mon Jun 16 2025

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE
SOUTHERN PLAINS TO THE SOUTHERN GREAT LAKES...

...SUMMARY...
Scattered thunderstorms with severe wind gusts and hail are expected
on Wednesday from the southern Plains to the southern Great Lakes.

...Mid Mississippi Valley/Ohio Valley/Southern Great Lakes...
A mid-level shortwave trough is forecast to move eastward through
the Upper Midwest on Wednesday. At the surface, a low is forecast to
deepen and move northeastward into the western Great Lakes, as a
cold front advances eastward into the mid Mississippi Valley. Ahead
of the front, surface dewpoints in the lower to mid 70s F will
contribute to moderate instability across much of the airmass by
afternoon. Thunderstorms are expected to develop along and ahead of
the front, with several convective clusters moving eastward toward
the stronger instability during the late afternoon and early
evening.

Model forecasts suggest that the strongest instability will be
located over the mid Mississippi and lower Ohio Valleys, while the
strongest deep-layer shear will be located in the southern Great
Lakes. The disjointed nature of the pattern could mean that the
severe threat could remain relatively unfocused. The current
thinking is that a broad corridor with an isolated severe threat
will develop during the afternoon. Supercells with hail will be
possible. However, it appears convection may tend to organize into
lines, which would result in the greatest severe threat being wind
damage. The severe threat is expected to move eastward into the
lower Great Lakes and into part of the Ohio Valley by early to mid
evening.

...Southern Plains/Ozarks...
The southern extent of a mid-level shortwave trough is forecast to
move through the southern Plains on Wednesday. By afternoon, a cold
front is forecast to be located from western Oklahoma to western
Missouri. To the southeast of the front, surface dewpoints in the
upper 60s to lower 70s F will likely enable moderate instability to
develop across much of the moist airmass by afternoon. As surface
temperatures warm during the day, convective initiation should take
place along and near the front. Multiple convective clusters appear
likely to initiate and move toward an axis of moderate instability
during the afternoon. NAM forecast soundings at 21Z near the
instability axis in Oklahoma and Missouri have 0-6km shear in the 30
to 35 knot range with 700-500 mb lapse rates of 7.5 to 8 C/km.
Supercells with large hail will be possible. However, storm mode may
tend to favor multicell lines or clusters with wind-damage
potential. The severe threat is expected to continue into the
evening, with the overall threat moving southeastward.

..Broyles.. 06/16/2025

$$