spc ac 200558
day 2 convective outlook
nws storm prediction center norman ok
1258 am cdt sat jun 20 2026
valid 211200z - 221200z
...there is a slight risk of severe thunderstorms from the central
high plains to parts of the mid-mississippi valley....
...summary...
severe storms are possible along a frontal zone from the
mid-mississippi valley to the central high plains on sunday. large
hail, severe winds, and tornadoes will be possible.
...synopsis...
a series of mid-level shortwave troughs will move through the
central portion of the conus along a surface frontal zone. the
primary surface low is expected to settle somewhere near the texas
panhandle on sunday with a weaker, perhaps convectively enhanced,
surface low across the midwest.
...ozarks into the lower ohio river valley...
an expansive mcs will likely be present across eastern kansas and
into missouri on sunday morning. this mcs will continue east through
the day and eventually into the ohio valley by the afternoon. an
outflow boundary will likely be left in the wake of this mcs across
missouri and southern illinois during the afternoon. the degree of
airmass recovery within this region remains uncertain. some guidance
shows a secondary mcs moving into northeast oklahoma and northern
arkansas, which may have implications on the upstream eml and the
potential for clearing/recovery in the wake of the morning mcs.
however, other guidance shows an eml advecting into the region and
aiding in recovery during the afternoon/evening. a localized
corridor with greater tornado threat likely exists along this
boundary from eastern missouri into southern illinois and perhaps
southwest indiana, but too much uncertainty from prior storms
precludes any higher tornado probabilities at this time.
...central high plains vicinity...
storms are forecast to develop within the upslope flow across
western kansas by mid-afternoon. easterly surface flow, combined
with strengthening flow aloft (in excess of 50 knots above 400mb)
will support supercell structures and the potential for large to
very large hail. storm motions will be relatively slow and thus, the
storms likely won't make it that far east due to increasing
inhibition with eastward extent. however, some guidance, most
notably the 00z hrw-nssl wrf show some elevated supercells farther
north into nebraska toward the end of the period. if this persists
in later guidance, an eventual eastward expansion of the slight risk
may be needed.
...southern kansas and northern oklahoma...
storms will continue to build westward during the day into eastern
and perhaps central kansas, and will congeal and shift southward
through the evening. overnight, as the low-level jet strengthens,
expect storms to develop in an area with moderate to strong
instability. these storms may pose some initial hail threat before
growing upscale into an mcs with a wind threat across southern
kansas and northern oklahoma during the overnight hours.
..bentley.. 06/20/2026
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note: the next day 2 outlook is scheduled by 1730z