spc ac 120547
day 2 convective outlook
nws storm prediction center norman ok
1247 am cdt sun apr 12 2026
valid 131200z - 141200z
...there is a slight risk of severe thunderstorms across the upper
midwest and across parts of the southern plains...
...summary...
severe thunderstorms are possible across the upper mississippi
valley and great lakes region, and across portions of the southern
plains on monday.
...synopsis...
the persistent/stagnant southwesterly flow regime will continue from
the southern plains to the upper midwest on monday. low-amplitude
upper ridging will move across the upper midwest during the day
ahead of a shortwave trough moving across the northern plains. the
shortwave will shift east across the great lakes overnight.
meanwhile, an upper trough from the northern rockies to offshore the
southern ca coast will pivot eastward toward the four corners
region. at the surface, low pressure near the sd/ne border will
develop east along the mn/ia border to central wi. meanwhile, lee
troughing will persist across the plains. a dryline will extend
southwest from the mid-mo valley into western ok/tx, while a warm
front extends from southern mn into southern/central wi. these
boundaries will become a focus for severe thunderstorm development
during the afternoon/evening.
...upper midwest...
strengthening southerly low-level flow will transport low to mid 60s
f dewpoints northward toward southern mn and southern/central wi.
meanwhile, a plume of steep midlevel lapse rates will overspread the
region. capping will likely suppress thunderstorm activity for much
of the day as the shortwave upper ridge moves across the region. by
late afternoon/early evening, height falls are forecast to
overspread the area and thunderstorms are expected to develop as a
strengthening low-level jet overspreads the warm front ahead of an
eastward-progressing surface low. initial thunderstorm activity may
be, or quickly become, elevated to the cool side of the warm front
given northeast storm motion. nevertheless, supercell wind profiles,
cool temperatures/steep lapse rates aloft, and moderate to strong
instability will support large hail potential.
if surface-based warm sector storms can develop, supercells capable
of all hazards will be possible. while this evolution is uncertain,
it appears most probable from southeast mn toward
south/south-central wi. convection will spread eastward with time
into mi, continuing to pose a risk for hail overnight.
...southern plains...
a conditional supercell environment will exist along/east of the
surface dryline from portions of western/central ok toward the tx
big bend. given a lack of height falls across the region, capping
will likely suppress convection. however, strong heating along the
dryline will promote mixing. confluence low-level flow along the
dryline coupled with strong instability and mixing may be sufficient
for a couple of storms during the late afternoon/evening as a modest
low-level jet develops. while conditional, if a storm can develop,
supercell wind profiles suggest large hail, strong gusts and perhaps
a tornado will be possible.
..leitman.. 04/12/2026
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note: the next day 2 outlook is scheduled by 1730z