Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
Issued by 15th OWS Scott Air Force Base IL
0245 PM CDT Thu Apr 23 2026
Valid 232000Z - 241200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS NORTH CENTRAL
MINNESOTA...EASTERN KANSAS...NORTHERN OKLAHOMA...
...SUMMARY...
Severe thunderstorms are expected to develop this afternoon and
evening from the southern through central Plains and Minnesota into
the lower to mid Missouri Valley, and upper Mississippi Valley.
Tornadoes, large hail and severe wind gusts will be possible.
...MN/IA to KS/northern OK this afternoon into tonight...
The interaction of a southeastward moving midlevel trough over
southern BC/AB and a northeastward moving trough over the western
Dakotas will lead to the formation of a deep closed low over
southern SK. An associated, occluding surface cyclone will weaken
across southern MB by this evening, as a trailing cold front moves
across MN/IA/KS/MO and northern OK. Low-level moisture will spread
northward across IA/MN in advance of the cold front, beneath the
northeast edge of an elevated mixed layer. Surface heating and the
degree of buoyancy may be limited by extensive clouds from IA into
MN, and forecast wind profiles show complex/messy hodographs
structures (stronger low-level shear lingering across IA). Mixed
convective modes are expected along and ahead of the front this
afternoon, which could produce occasional wind damage, large hail
and perhaps a couple of tornadoes.
The more substantial severe threat is expected late this afternoon
through late evening from eastern KS into northern OK, near and just
northeast of a cold front/dryline triple point and weak secondary
cyclone. A midlevel speed max near the Four Corners will progress
eastward to the TX Panhandle by this evening, with ascent in the
left exit region of the jet coincident with the triple point near or
just north of the KS/OK border. An influx of mid 60s boundary-layer
dewpoints beneath steep midlevel lapse rates will contribute to
MLCAPE of 2000-3000 J/kg, with weakening convective inhibition
across KS by mid afternoon.
Storm development is expected along the cold front in KS by mid
afternoon, with storms expected to develop southward to near the
triple point. The large buoyancy, steep midlevel lapse rates and
deep-layer shear sufficient for supercells will favor very large
hail (2-3 inches in diameter) with the initial/more discrete storms.
The tornado threat will peak this evening as low-level
shear/hodograph curvature increase near the KS/OK border - there
will be strong tornado potential with the anchor/southern supercells
near the triple point. Upscale storm growth and cold pool
development will favor a more linear convective mode with occasional
wind damage as the outflow/effective cold front spreads
southeastward into northeast OK and southwest MO overnight.
...OK dryline this evening...
Storm development along the dryline in OK is uncertain late this
afternoon/evening. Forecast soundings suggest that the degree of
surface heating/mixing along the dryline and residence time in the
dryline circulation will be close to supporting deep convection. If
storms do form, the environment will conditionally favor very large
hail initially, and the possibility of an evening tornado threat
with any sustained storm.
..Afwa.. 04/23/2026
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