ACUS02 KWNS 250536
SWODY2
SPC AC 250534

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Sat Apr 25 2026

Valid 261200Z - 271200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE SUNDAY
INTO SUNDAY NIGHT ACROSS MUCH OF CENTRAL AND EASTERN KANSAS...
ADJACENT PORTIONS OF SOUTHERN NEBRASKA AND WEST CENTRAL MISSOURI...

...SUMMARY...
Isolated to widely scattered severe storms with potential to produce
large hail and a couple of strong tornadoes are possible by early
Sunday evening across parts of the central and southern Great
Plains, before one or two organizing clusters of storms spread
toward the middle/lower Missouri Valley with potentially damaging wind gusts.

...Discussion...
Models continue to indicate that a remnant elongated cyclonic
mid-level circulation will tend to redevelop north-northeastward
through Saskatchewan/Manitoba during this period, within generally
weakening larger-scale troughing extending along an axis inland of
the U.S. Pacific coast through the Hudson Bay vicinity. At the same
time, mid/upper ridging across southern/central Mexico into portions
of the southern Great Plains and lower Mississippi Valley appears
likely to maintain considerable strength, as a notable short wave
perturbation accelerates out of the southern Great Basin/lower
Colorado Valley, within southwesterly flow which is likely to
strengthen across the southern Rockies through central Great Plains
late Sunday through Sunday night.

There appears a bit more disparity within guidance concerning when
the stronger mid-level height falls associated with the primary
impulse spread across the Rockies through the eastern
Colorado/western Kansas/southwest Nebraska vicinity of the high
plains. It now appears that it may not be until early evening or
later, but it does appear that this may be preceded by a more subtle perturbation across the same vicinity, perhaps as early as Sunday
morning. The lead wave may be accompanied by one developing surface
low within lee surface troughing across central Nebraska into the
mid Missouri Valley, while the trailing wave supports the eastward
migration of another surface cyclone out of southeastern Colorado
into central Kansas late Sunday through 12Z Monday.

In response to these developments, seasonably moist low-level air,
initially confined to the southern Great Plains, perhaps as far
north as central Oklahoma at the outset of the period, may tend to
advect in a corridor ahead of a sharpening dryline across western
Oklahoma into western Kansas by late afternoon. Downstream, models
suggest that warm advection, at least in lower/mid-levels, will
strengthen and become focused in a corridor across north central
through northeastern Kansas by late Sunday evening, near the nose of
a plume of warm and more strongly capping elevated mixed-layer air.

...Central/Southern Great Plains...

Latest model output, including convection allowing guidance, has not
offered much more in the way of clarity concerning convective
potential for this period. Among other issues, the plume of warm
elevated mixed-layer air advecting northeastward through the
southern and central Great Plains may prove inhibitive to the
initiation of storms across much of the developing warm sector,
while also contributing to moderate to strong potential instability.
Potential for early day convection across western Kansas and
adjacent portions of the high plains may also impact later day
severe weather potential.

Even so, guidance generally indicates that a cyclonically curved,
50-70+ kt 500 mb jet streak will nose across the Texas/Oklahoma
Panhandle region by early Sunday evening. This likely will
contribute to strengthening convergence along a sharpening dryline, particularly across portions of western Kansas, where at least a
narrow corridor of moderate boundary-layer destabilization probably
will become supportive of supercell development. The potential for
a couple of strong tornadoes probably will increase as cells
propagate east-northeastward Sunday evening, in the presence of
enlarging clockwise curved hodographs beneath a strengthening
southerly low-level jet (including 40-50+ kt around 850 mb).
Tornadic potential probably will maximize during the mid to late
evening, before convection consolidates and grows upscale into one
or more clusters, in the presence of forcing for ascent aided by
strengthening lower/mid-tropospheric warm advection across north central/northeastern Kansas and adjacent portions of the Great Plains.

..Kerr.. 04/25/2026

$$

--- ScorpioBBS/QWK v0.32a (Linux/x86_64)
* Origin: Project Scorpio TEST (618:250/6)

ACUS02 KWNS 260545
SWODY2
SPC AC 260543

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

$$

--- ScorpioBBS/QWK v0.32a (Linux/x86_64)
* Origin: Project Scorpio TEST (618:250/6)