RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1254 AM CDT Wed Apr 22 2026
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE HIGH PLAINS AND FROM NORTHEAST INDIANA INTO CENTRAL AND NORTHERN
OHIO...
...SUMMARY...
Severe thunderstorms with hail and isolated severe gusts will be
possible across parts of the High Plains this afternoon and evening.
Isolated severe gusts and hail will also be possible in parts of
northeast Indiana and Ohio.
...High Plains...
At mid-levels today, heights will fall across much of the High
Plains, as a ridge moves toward the Mississippi Valley and a trough
moves through the Intermountain West. In response, a lee trough will
sharpen across the High Plains. To the east of the surface trough,
moisture advection will take place. Surface dewpoints will increase
into the 55 to 60 F range to the east of a well-developed dryline
extending from west Texas northward into southwest Nebraska.
Although large-scale ascent will be weak along the dryline,
low-level convergence will aid isolated convective initiation during
the mid to late afternoon. The most favorable location for storm
development will be from northwest Kansas into west-central Nebraska
and southern South Dakota, as the low-level jet strengthens in the
late afternoon and early evening. In addition to moderate
instability, 0-6 km shear is forecast to increase into the 35 to 40
knot range by early evening. This, combined with 700-500 mb lapse
rates in the 8.5 to 9 C/km range should be favorable for supercells
with isolated large hail, with the greatest potential from northwest
Kansas into west-central Nebraska. A few severe wind gusts may also
occur from western Kansas into South Dakota.
Further south into west Texas and the Oklahoma Panhandle, the lift
supportive of convective development will be confined to weak
low-level convergence along the dryline. If a storm can initiate,
then a supercell could develop with potential for large hail.
...Northeast Indiana/Central and Northern Ohio...
A mid-level ridge will move into the upper Mississippi Valley today,
as northwesterly mid-level flow persists over the Great Lakes
region. At the surface, a slow-moving front will remain in place
from southern Wisconsin eastward into southern Michigan. Scattered
thunderstorms will develop this afternoon along and to the south of
the front as surface temperatures warm and low-level convergence
increases. Model forecasts in the mid to late afternoon from
northeast Indiana into central and northern Ohio have MLCAPE in the
2000 to 2500 J/kg range, with 0-3 km lapse rates near 8.5 C/km. In
addition, 0-6 km shear is forecast to approach 30 knots, which could
be enough for a marginal severe threat. Isolated severe gusts and
hail will be possible with the stronger multicells in areas that
destabilize the most.
..Broyles/Chalmers.. 04/22/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Wed Apr 22 2026
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
KANSAS INTO SOUTHERN MINNESOTA...
...SUMMARY...
Severe thunderstorms will be possible from southern Kansas into
southern Minnesota on Thursday. Large hail to very large hail,
damaging winds, and a few tornadoes are possible.
... Synopsis ...
A shortwave trough will move northeast along the eastern periphery
of a western US longwave trough. This shortwave will help maintain a
surface cyclone in southern Canada, while a secondary surface low
may develop across southern Minnesota late in the period. A
secondary shortwave will approach the southern Plains late in the
forecast period.
As the shortwave trough lifts northeast, a cold front will
accelerate east across the central and northern Plains. Ahead of the
surface front southerly winds will support mid 50F dewpoints as far
north as northern Minnesota and pockets of 60F dewpoints perhaps as
far north as southern-to-central Minnesota.
... Central and Northern Plains ...
Diurnal heating of the moist airmass ahead of the advancing surface
front will yield an increasingly unstable atmosphere during the
afternoon with the 20260422/00Z HREF showing ensemble mean SBCAPE
values approaching 2000 J/kg as far north as the greater Omaha, NE,
vicinity by 20Z. Interrogation of forecast soundings ahead of the
frontal boundary shows a strong cap stretching from Oklahoma
northward into Nebraska and Iowa. This cap does lift during the day
in response to increasing large-scale ascent from the approaching
trough, but thunderstorm initiation will likely require convergence
along the surface front.
This should occur by mid-afternoon anywhere from northeast Kansas
into southern Minnesota. Initially, deep-layer shear is not
particularly strong across the warm sector, but would still support
a combination of multi-cells and supercells. Given the degree of
instability and steep midlevel lapse rates, large-to-very-large hail
would be possible with any of these initial storms. A tornado or two
would also be possible given some low-level curvature in the
forecast hodographs associated with at least a modest low-level jet.
As the cold front continues to move east into the moist and unstable
airmass, additional thunderstorms should develop along the front,
eventually growing upscale into one or more linear systems and a
transition to a damaging wind threat. Vertical shear should improve
during the late afternoon and evening as the mid-to-upper-level
winds respond to the approach trough, yielding a continued tornado
threat with any persistent discrete cell.
... Oklahoma and Northwest Texas ...
A very unstable airmass will develop across the region to the east
of a dryline across western Oklahoma during the afternoon. Forecast
soundings show varying degrees of a cap across Oklahoma and
Northwest Texas. With the strongest large-scale ascent remaining
largely to the north of the area, forcing for ascent will likely
require strong dryline circulations. Given afternoon temperatures in
the 90Fs to the west of the dryline, there is at least some
potential for dryline circulations to break the cap and initiate at
least a couple of storms. Vertical shear profiles will support
supercells capable of very large hail. A highly conditional tornado
threat could develop with any discrete storm that is able to move
off the dryline and into the increasingly moist and unstable
environment to the east.
..Marsh.. 04/22/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0221 AM CDT Wed Apr 22 2026
Valid 241200Z - 251200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY...
...SUMMARY...
A few severe thunderstorms will be possible across portions of the
Southern Plains into the Lower Mississippi Valley on Saturday. Large
hail and damaging wind gusts should be the primary threats.
... Synopsis ...
A persistent longwave trough will remain situated across the
northern US on Friday, maintaining a broad regime of cyclonic
midlevel flow over the western two-thirds of the country. Within
this broad flow, neutral to modest midlevel height rises are likely
across the Southern Plains. This evolution suggests a lack of robust
large-scale forcing for ascent, with subtle subsidence potentially
acting as a limiting factor for widespread convective coverage.
... Southern Plains into the Lower Mississippi Valley ...
At the start of the forecast period, convective activity may be
ongoing across portions of northeast Oklahoma, southeast Kansas,
southern Missouri, or northern Arkansas along a consolidated outflow
boundary/cold front. These storms should slowly weaken during the
morning with the loss of large-scale ascent and a weakening
low-level jet. The outflow boundary/cold front should slowly sag
south through the morning before stalling somewhere in the vicinity
of the I40 corridor. This feature will serve as the primary focus
for subsequent development later in the afternoon, with residual
outflow or differential heating boundaries being a secondary source
of initiation.
South of the frontal boundary, a highly unstable airmass will remain
in place across the warm sector. Strong diabatic heating of a moist
boundary layer will yield pockets of moderate-to-strong instability,
with MUCAPE values potentially in the 2000-3000 J/kg range. While
deep-layer shear is forecast to remain relatively modest (30-35
knots), the degree of instability will be sufficient to support
robust updrafts.
Given the modest shear and lack of stronger synoptic support, storm
modes will likely be multicell clusters or transient supercells. Any
persistent cell will be capable of producing large hail and
localized damaging wind gusts
... Lower Mississippi Valley ...
Convection that develops across Oklahoma and Arkansas during the
afternoon is expected to persist into the evening as it moves slowly
east-southeast toward Mississippi and Tennessee. Although
instability is not as great with eastward extent, it should remain
sufficient enough to support some potential for sporadic wind and
hail through the overnight hours.
..Marsh.. 04/22/2026
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