808
ACUS03 KWNS 260730
SWODY3
SPC AC 260729

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Wed Jun 26 2024

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
SOUTHEAST NE...NORTHEAST KS...CENTRAL/SOUTHERN IA...NORTHERN
MO...WESTERN IL...

...SUMMARY...
Severe thunderstorms may develop from parts of the central Plains
into parts of the upper Midwest and upper Mississippi Valley on
Friday. Large hail, damaging wind, and a couple tornadoes will be
possible.

...Central/northern Plains into the upper Midwest/Great Lakes...
A mid/upper-level trough will move eastward across the northern
Great Plains into the upper Great Lakes region on Friday into Friday
night. In conjunction with the shortwave, a surface low will move
eastward across the Dakotas, with secondary low development possible
across the central Plains. A warm front is forecast to move
northward across the mid/upper MS Valley, while a cold front will
move through the northern/central Plains into MN through the day and
into the evening.

Widespread convection will likely be ongoing at the start of the
period, within a warm-advection regime. In the wake of the morning
convection, moderate to locally strong destabilization will be
possible in the vicinity of the cold front and a possible outflow
boundary across parts of NE/IA into northeast KS/northwest MO, with
somewhat more modest destabilization along the northward extension
of the front into the eastern Dakotas and parts of MN/WI.

The strongest mid/upper-level flow will move across the Dakotas into
Minnesota, though modest westerlies farther south will support
sufficient effective shear for some storm organization, both in the
vicinity of the cold front and any outflow boundaries, and also
within the post-frontal regime into parts of the central High
Plains.

Storm evolution during the afternoon/evening remains somewhat
uncertain, but development of a few supercells and/or stronger
clusters will be possible, both near the cold front somewhere from
southeast NE and IA into northeast KS and northern MO, and also
within a potentially favorable post-frontal regime across the
central High Plains. Large hail and localized severe gusts will be
possible initially, along with some tornado potential, especially if
any supercells can develop within a belt of stronger low-level
flow/shear currently forecast from eastern KS into northern MO,
southern IA, and western IL.

Farther north, the magnitude of destabilization remains rather
uncertain into the eastern Dakotas and Minnesota, but strong
deep-layer shear will support a conditional supercell threat, if
sufficient pre-frontal buoyancy develops. A hail and severe-wind
threat would accompany any persistent deep convection within this
regime.

A Slight Risk has been included where confidence is currently
greatest regarding storm coverage within a favorable environment,
from southeast NE/northeast KS into central/southern IA, northern
MO, and western IL.

Storm coverage is less certain across the eastern Dakotas and
Minnesota, while the corridor of the most favorable post-frontal
environment is also uncertain across the central High Plains.
Greater probabilities may eventually be needed for those areas as
well, depending on the resolution of these uncertainties.

..Dean.. 06/26/2024

$$