RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0737 AM CDT Wed Apr 22 2026
Valid 221300Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FOR PARTS OF THE HIGH PLAINS/NORTHERN PLAINS...AND
FROM NORTHEAST INDIANA INTO NORTHERN OHIO...
...SUMMARY...
Isolated strong-severe thunderstorms with strong gusts and hail will
be possible across parts of the High Plains this afternoon and
evening, as well as from northeast Indiana into northern Ohio.
...High Plains this afternoon/evening...
In response to a shortwave trough digging south-southeastward over
BC/AB, a closed low over the Great Basin will evolve into a more
open wave and eject northeastward to the northern High Plains by
early Thursday. An associated, deep lee cyclone will develop
eastward from MT to near the ND/SK border, with a lee trough
extending southward into the central/southern High Plains. East of
the lee trough, low-level moisture (boundary-layer dewpoints in the
55-60 F range) will spread northward today from TX/OK to KS/NE.
Diurnal mixing will likely limit the quality of the moisture farther
north into the Dakotas. Thus, a few high-based thunderstorms will
be possible this afternoon/evening from NE into SD along the lee
trough with deep mixing, where inverted-v profiles will favor strong
outflow gusts.
A narrow zone of moderate buoyancy is expected along the dryline
from southwest NE and western KS into west TX, where deep-layer
vertical shear will be sufficient for supercells. Only limited
height falls and a warm elevated mixed layer, in combination with
somewhat limited parcel residence times in the dryline circulation,
suggest that storm coverage will be isolated at best. There will be
a conditional threat for isolated large hail with any sustained
storms.
...Dakotas tonight...
The threat for thunderstorms may increase tonight as a result of
ascent preceding the midlevel trough, and a modest increase in
low-level moisture with a strengthening low-level jet. Much of the
convection will likely be rooted above the surface, but could still
produce strong outflow gusts and marginally severe hail.
...IN/OH this afternoon/evening...
Residual low-level moisture and surface heating along a diffuse
baroclinic zone will support thunderstorm development this afternoon
from northeast IN into northern OH. Though deep-layer wind profiles
will not be particularly strong, relatively cool midlevel
temperatures and weak-moderate buoyancy could support marginally
severe hail and gusty outflow winds with the strongest storms.
..Thompson/Bentley.. 04/22/2026
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