spc ac 230609
day 2 convective outlook
nws storm prediction center norman ok
0109 am cdt tue jun 23 2026
valid 241200z - 251200z
...there is a slight risk of severe thunderstorms across portions of
the central/southern high plains....
...summary...
widely scattered severe storms are possible across the central high
plains on wednesday with a threat for large to very large hail and
severe wind gusts. more isolated severe storms are possible across
portions of the upper midwest, ozarks to mississippi, and across
northern utah.
...synopsis...
moderate northwesterly mid-level flow will be present from the
northern rockies to the midwest between a ridge across the southwest
and a trough moving across southern canada into the upper midwest. a
weak mid-level shortwave trough will likely be in the arkansas
region at the beginning of the period and weaken with a secondary
mid-level shortwave trough moving across the central rockies and
deamplifying the ridge. at the surface, a weak surface low will move
from northern minnesota into wisconsin. a secondary lee cyclone will
develop across eastern colorado in response to the approaching
mid-level shortwave trough and strengthening mid-level flow.
...central/southern high plains...
moderate to strong instability is forecast to develop within upslope
flow across eastern colorado and southeast wyoming on wednesday
afternoon. as 40 to 50 knots of mid-level flow advects over the
region, a favorable supercell environment will be in place.
supercells are likely to develop by mid afternoon with an initial
threat of large to very large hail and severe winds. the more
organized supercell threat is forecast from east-central colorado
northward where the 15% hail probabilities are confined. 15% wind
probabilities continue farther south as forecast soundings suggest
severe winds (perhaps 75+ mph) are likely, even if storms are less
organized.
...ks/ok into the ozarks...
day 1 convection will have a considerable impact on the coverage and
severity of severe storms on wednesday. some guidance shows morning
storms along a frontal zone in oklahoma and persisting into the
afternoon which will stabilize most of the region into the afternoon
and evening. however, if these storms do not form, a very favorable
airmass will remain in place and a mcs could develop across the high
plains and move into this region tuesday night. this could bring
some severe weather threat and it would have implications for where
destabilization would be on day 2/wednesday. therefore, a broad 5%
driven by severe winds seems appropriate at this time and additional
refinement can be made once the impact of prior day convection
becomes more clear.
...western great lakes...
lingering clouds associated with early-day storms may limit air mass
destabilization into afternoon. however, where cloud breaks can
occur, the combination of cooling temperatures aloft and modest
boundary-layer moisture content will support moderate afternoon
instability. widely scattered thunderstorms are expected to develop
during the afternoon in the vicinity of the surface low and frontal
boundary, and within the belt of stronger mid-level flow, suggesting
some potential for large hail with the strongest updrafts.
...eastern arkansas into mississippi...
there is considerable uncertainty regarding the coverage of storms
across arkansas at 12z wednesday, but given forcing from a mid-level
trough and moderate to strong instability across the region, either
re-intensification of morning convection or additional afternoon
convection is possible within this zone. damaging winds will be the
primary threat.
...northern utah...
a weak mid-level shortwave trough will move across northern utah
during the day on monday with weak to moderate instability. forecast
soundings show a deeply-mixed sub-cloud layer which may result in
severe winds. some consideration was given to a cig1 area given the
potential for organized storms in the steep lapse rate environment,
but did not have the confidence for 75+ mph wind gusts to add it at
this time.
..bentley.. 06/23/2026
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note: the next day 2 outlook is scheduled by 1730z