673
ACUS02 KWNS 281700
SWODY2
SPC AC 281658

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1158 AM CDT Sun Jun 28 2026

Valid 291200Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS AND UPPER MIDWEST...

...SUMMARY...
Severe thunderstorms are possible from parts of the central/northern
Plains into the Upper Midwest on Monday. Large hail and severe winds
are the primary concerns, though a couple of tornadoes may also
occur.

...Synopsis...

An upper low and attendant shortwave trough, initially over the
northern Rockies, will eject east/northeast across the northern
Plains on Monday. This will bring a belt of enhanced mid/upper
south/southwesterly flow across parts of the northern/central Plains
to the Upper Midwest. At the surface, low pressure will deepen over
SD and lift north/northeast through evening. A trailing cold
front/dryline will move across the Dakotas and portions of NE after
00z while a warm front lifts northward across parts of eastern ND
and northern MN through the day. A secondary lee surface low will
develop over the central High Plains, with a dryline extending
south/southwest across western KS into southwest TX.

...Dakotas/Mid-MO Valley/Upper Midwest...

Uncertainty over mesoscale details persists this forecast cycle,
though overall model guidance continues to show better agreement.
Convection appears likely to be ongoing Monday morning across the
central Dakotas near the deepening surface low and northward
extending frontal occlusion. This activity may be elevated, but
supercell wind profiles are evident in forecast soundings with
elongated/straight hodographs noted amid 50+ kt effective shear
magnitudes. A plume of steep midlevel lapse rates will be in place
across the region and elevated convection will pose a risk for large
to very large hail early in the day as storms move northward.

A very moist and unstable airmass will reside across the region,
with strong to extreme instability depicted in forecast guidance.
Convective evolution is uncertain. The extent of morning convection
could augment the northward extent of the richer boundary layer
moisture and instability. Guidance also varies in regards to the
evolution of the surface low, with some guidance being slower and
other solutions much faster. Nevertheless, the surface low/triple
point, warm front, and surface tough/cold front will be areas for
concern for convective development during the day and into the
afternoon. If supercells can develop and be surface-based near the
warm front, an all-hazards severe risk is evident given the very
favorable thermodynamic and kinematic parameter space. While initial
supercells are possible during the evening along the cold front from
the Mid-MO Valley into southern MN, boundary-parallel deep-layer
flow and an intensifying low-level jet could result in rapid upscale
growth into a bowing segment during the nighttime hours. This could
result in an increase in damaging wind potential if nighttime
convection can be near-surface based.

...KS/OK/TX...

Isolated to scattered high-based thunderstorms are likely during the
evening along the dryline. Instability and vertical shear will be
modest, limiting longevity of stronger updrafts. Nevertheless, a
deeply mixed boundary layer with inverted-v sub-cloud thermodynamic
profiles could support strong outflow gusts. Overall severe
potential appears limited, precluding marginal probabilities at this
time.

...Southeast...

Moderate instability will develop amid a seasonally moist airmass
near the Savannah River into GA Monday afternoon/early evening. A
backdoor/wedge front is expected to push south/southwest across SC
and may contribute to isolated to scattered thunderstorm development
by peak heating within a deep-layer northwesterly flow regime.
Vertical shear will be weak, but occasional sub-severe gusty
outflows will be possible, mainly across central/southern GA.

..Leitman.. 06/28/2026

$$