SPC Jun 28, 2025 1730 UTC Day 2 Convective Outlook

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1230 PM CDT Sat Jun 28 2025

Valid 291200Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER
MIDWEST INTO THE LOWER MISSOURI VALLEY...

...SUMMARY...
Scattered strong to severe storms are possible Sunday from the
central Plains into the upper Great Lakes region, with some
potential for the evolution of a large, organized severe storm
cluster across parts of the mid into lower Missouri Valley and
central Great Plains late Sunday through Sunday night.

...Synopsis...
An amplifying midlevel trough will advance east-southeastward from
the north-central Plains toward the Upper MS Valley through the
period. Related large-scale ascent will overspread the Middle/Upper
MS Valley, while a related cold front moves southeastward across the
region.  

...Upper Midwest...
In the wake of several overnight storm clusters and related cloud
debris, gradual clearing should support boundary-layer
destabilization and the development of moderate-strong surface-based
buoyancy. As the cold front intercepts this increasing buoyancy,
around 30 kt of deep-layer shear should favor a few organized
clusters capable of producing widely scattered damaging wind gusts
during the afternoon.

...Central Plains to the Middle/Lower Missouri Valley...
A separate area of thunderstorms is expected along the front in IA
and the Lower MO Valley during the late afternoon into the overnight
hours. Ahead of these evolving storms, lower/middle 70s dewpoints
beneath steep midlevel lapse rates will contribute to strong-extreme
surface-based buoyancy. Initial storms will be capable of producing
isolated large hail and locally severe wind gusts. However,
strengthening deep-layer shear accompanying the digging midlevel
trough, coupled with an increasing low-level jet, will support the
development of a southward-moving MCS into the overnight hours. The
Slight risk was expanded southward to account for this scenario, and
higher wind probabilities may eventually be needed as the scenario
becomes more clear. 

Farther west, semi-discrete storms are expected over the central
High Plains during the afternoon. Elongated/straight hodographs and
moderate surface-based buoyancy should favor large hail with any
supercell structures that can develop.

...Mid-Atlantic...
Despite marginal deep-layer flow/shear, diurnal heating amid deep
tropospheric moisture (around 2 inch PW) will favor wet microbursts
and the potential for wind damage with the stronger thunderstorms.

..Weinman.. 06/28/2025

StormPrep