RSS Mesoscale Discussions from Storm Prediction Center
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Sat Apr 25 2026
Valid 260100Z - 261200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHEAST OKLAHOMA AND FAR NORTHEAST TEXAS...
...SUMMARY...
Severe thunderstorms with a potential for large to very large,
tornadoes and severe wind gust will continue this evening into
tonight across parts of the southern Plains and Ark-La-Tex.
Additional severe storms with hail and isolated severe gusts will be
possible in parts of the central Plains.
...Southern Plains/Ark-La-Tex...
A low-amplitude mid-level shortwave trough is evident on water vapor
imagery from east-central Kansas southward into west-central
Oklahoma. At the surface, a moist airmass is located over the
eastern part of the southern Plains into the Ark-La-Tex, where
surface dewpoints are in the mid 60s to the mid 70s F. The RAP shows
strong instability across north Texas and southern Oklahoma, with
MLCAPE in the 3000 to 4000 J/kg range. Scattered severe storms are
ongoing near an instability maximum that is near the Red River north
of the Dallas/Fort Worth Metroplex. The RAP is also showing very
steep mid-level lapse rates over southern Oklahoma and far north
Texas. 700-500 mb lapse rates are estimated to be in the 7.5 to 8
C/km range. This will be favorable for large to very large hail.
Hailstones of 2 to 3 inches in diameter will be possible with the
more intense supercells.
In addition, a low-level jet is analyzed from northeast Texas into
eastern Oklahoma. The low-level jet has not strengthened as much as
was originally forecast, but is still expected to gradually ramp up
over the next few hours. This will increase low-level shear
maintaining a tornado threat. The RAP still increases 0-3 km
storm-relative helicity into the 350 to 400 m2/s2 range within a
couple of hours, suggesting that a potential for strong tornadoes
will continue. A wind-damage threat is also expected to be
maintained this evening into the early overnight period, as a severe
convective cluster moves southeastward toward the Ark-La-Tex.
Concerning the placement of the Moderate, it appears that severe
threat coverage will be more limited north of I-40. For this reason,
the northern extent of the Moderate Risk area has been trimmed.
...Central Plains...
Water vapor currently shows a subtle shortwave trough moving into
the mid Missouri Valley and another one moving into the central High
Plains. At the surface, a moist airmass is located from central and
eastern Kansas into far southeast Nebraska, where scattered
thunderstorms are ongoing. Across this area at mid-levels, flow is
generally from west to southwest at 30 to 40 knots. This is creating
sufficient deep-layer shear for organized severe storms. Steep
mid-level lapse rates will be favorable for isolated large hail.
Severe wind gusts will also be possible.
..Broyles.. 04/26/2026
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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 AM CDT Sun Apr 26 2026
Valid 261200Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS...
...SUMMARY...
Scattered severe storms with large to very hail, damaging wind gusts
and tornadoes are expected this afternoon and evening across parts
of the central and southern Plains. Strong tornadoes and hailstones
greater than 2 inches in diameter will be possible. Hail and
isolated severe gusts will also be possible in parts of the
Ark-La-Tex and lower Mississippi Valley.
...Southern and Central Plains...
A vigorous mid-level trough will eject northeastward toward the
southern and central Rockies this afternoon into tonight, as an
associated mid-level jet translates east-northeastward through the
Desert Southwest. The exit region of the mid-level jet will
overspread the central Plains by this evening providing lift and
strong deep-layer shear, favorable for severe storms. At the
surface, a lee trough will deepen over the southern and central High
Plains, as moisture advects northward from Oklahoma into Kansas.
Throughout most of the day, large-scale ascent will be limited over
the moist sector. Isolated thunderstorms with hail and severe gusts
will be possible in areas with maximized low-level convergence and
strong instability. Convective coverage will likely increase during
the evening as the mid-level jet max approaches, and as a 40 to 50
knot low-level jet strengthens. By mid to late evening and into the
overnight period, scattered severe storms will be likely in parts of
the central Plains and Ozarks, with isolated storms possible in the
southern Plains.
Model forecasts suggest that a pocket of strong instability will be
in place over Oklahoma early this evening, but that a capping
inversion will exist over much of the moist sector. RAP forecast
soundings at Salina, Kansas gradually erode the capping inversion
during the evening as low-level moisture increases. By late evening
in central Kansas, MUCAPE is forecast to be in the 4500 to 5000 J/kg
range with 0-6 km shear near 50 knots. 700-500 mb lapse rates are
forecast to be very steep and could exceed 8 C/km. This should be
favorable for supercells with large to very large hail. Hailstones
greater than 2 inches in diameter will be possible. Although the
storms will likely be elevated during much of the evening, some
cells could become surface-based in the mid to late evening or early
overnight period. Once this occurs, a tornado threat should develop.
The more intense supercells could produce a strong tornado or two. A
wind-damage threat will also be possible.
Further south into parts of Oklahoma, limited large-scale ascent
will make initiation difficult along the dryline. If a storm can
become established during the late afternoon or early to mid
evening, extreme instability (MLCAPE near 5000 J/kg) and steep
mid-level lapse rates near 8 C/Km will be very favorable for large
to very large hail. 0-3 km storm-relative helicity around 250 m2/s2
would also support a tornado threat.
...Ark-La-Tex/Lower Mississippi Valley...
The eastern edge of a moist and unstable airmass will be located in
the lower Mississippi Valley today. Although large-scale ascent will
be weak due to the presence of a mid-level ridge, isolated
convective initiation will be possible in areas that locally heat up
the most. Cells that can strengthen in the late afternoon and early
evening could produce isolated severe gusts and hail.
...Central and Southwest Texas...
The western edge of an extremely unstable airmass will be located
from central Texas into southwest Texas this afternoon. Isolated
thunderstorm initiation will be possible just to the east of a
dryline, as low-level convergence increases late this afternoon. The
extreme instability (MLCAPE of 4000 to 5000 J/kg) with moderate
deep-layer shear and steep mid-level lapse rates would be favorable
for isolated large hail and strong wind gusts.
..Broyles/Moore.. 04/26/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1243 AM CDT Sun Apr 26 2026
Valid 271200Z - 281200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS MONDAY
AFTERNOON THROUGH MONDAY EVENING ACROSS MUCH OF THE MIDDLE
MISSISSIPPI VALLEY...INCLUDING PORTIONS OF SOUTHEASTERN
IOWA...SOUTHERN WISCONSIN..EASTERN MISSOURI...MUCH OF ILLINOIS...AND
PORTIONS OF NORTHEASTERN ARKANSAS...NORTHWESTERN TENNESSEE AND
WESTERN INDIANA...
...SUMMARY...
Widespread strong to severe thunderstorm development appears
probable across the middle Mississippi into lower Ohio Valleys
Monday afternoon through Monday evening, accompanied by potential
for a few strong tornadoes, damaging wind gusts and large hail.
...Discussion...
Models suggest that the northern periphery of a prominent
subtropical high, centered near the Mexican Gulf coast, may build a
bit further northward through the southern Great Plains and
Gulf Coast states through this period. This is forecast to occur
downstream of a digging mid/upper trough and embedded low across the
southern mid- to subtropical latitudes of the eastern Pacific, while
broad, larger-scale troughing to its north progresses eastward
through much of the interior of North America.
Near the leading edge of the latter regime, it appears that a
significant short wave perturbation will accelerate northeast of the
lower Missouri Valley through the Upper Midwest/Great Lakes region,
accompanied by a notable (sub-1000 mb) deepening surface cyclone. A
trailing low may migrate from east central Kansas through eastern
Iowa during the day Monday, trailed by a dryline just ahead of a
cold front, which may gradually overtake the dryline across eastern
Iowa through southwestern Missouri late Monday afternoon into
evening. It appears that this may be preceded by one or two
clusters of storms maintained by forcing for ascent associated with
lower/mid-tropospheric warm advection, which may still be ongoing
across northern Missouri/southern Iowa into parts of northern and
central Illinois at the outset of the period, before shifting
eastward into the Ohio Valley during the day.
The impacts of this potential activity on subsequent destabilization
and convective development remains unclear, and a significant source
of lingering forecast uncertainty. However, most guidance continues
to indicate moderate to strong warm sector boundary-layer
destabilization will occur with low-level moisture return and
insolation beneath an initially northeastward advecting plume of
capping elevated mixed-layer air, ahead of the dryline. Substantive
destabilization still appears possible to the cool side of an
outflow boundary generated by the early day convection, which may
retreat northward through parts of southeastern Iowa and central
through northern Illinois by late afternoon, as an effective warm
frontal zone to the east of the southern surface low.
...Middle Mississippi into lower Ohio Valleys...
Aided by mid/upper forcing for ascent to the poleward side of a 70+
kt southwesterly, cyclonic 500 mb jet streak, it appears that the
triple point low/dryline may become the focus for strongest storm
development by late Monday afternoon across parts of northeastern
Missouri/southeastern Iowa into northwestern Illinois. Given the
environment, including sizable clockwise-curved low-level hodographs
beneath 40-50 kt southerly 850 mb flow, this probably will include
discrete supercells initially, with potential to produce large hail
and strong tornadoes. Gradually, it is probable that this will grow
upscale along the remnant outflow boundary and along the dryline as
it begins to be overtaken by the southward surging cold front, into
the lower Ohio Valley by late Monday evening. As this occurs,
embedded supercell structures may continue to pose a risk for strong
tornadoes, with evolving meso-vortices along developing gust fronts
of convective outflow also posing a risk for brief tornadoes and/or
damaging wind gusts.
The extent of the tornadic threat remains a bit unclear, and will
probably be dependent on how long discrete supercells are maintained
along/ahead of the dryline. However, depending on how the modifying
initial convective outflow evolves across southeastern Iowa into
central Illinois, this boundary could become a focus for heightened
tornado potential, with a few strong, and particularly damaging,
tornadoes possible. Categorical and severe probabilities could
still be upgraded further in later outlooks for this period.
..Kerr.. 04/26/2026
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