Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0248 PM CDT Sun May 24 2026
Valid 242000Z - 251200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
NORTHEAST NEBRASKA...SOUTHEASTERN SOUTH DAKOTA...NORTHWEST IOWA AND
SOUTHWEST MINNESOTA...
...SUMMARY...
Severe storms capable of hail/wind may occur across the Middle
Missouri Valley/Siouxland later this afternoon into evening, with
isolated severe storms also possible this afternoon/early evening
across other parts of the central and southern Plains and Southeast.
...20z Update...
No major changes were made to the prior outlook. Isolated to widely
scattered thunderstorms, with a few supercells, appear probable
across parts of the central High plains/Midwest late this afternoon
into this evening. Moderate buoyancy and 35-40 kt of effective shear
associated with west-northwesterly flow aloft could support
supercells capable of large hail in the presence of steep lapse
rates.
Elsewhere, moderate to strong buoyancy and weak shear will
predominate. Scattered thunderstorms over much of the Southeast and
North/central TX will be capable of sporadic damaging gusts with
downbursts. 5% wind probabilities were expanded slightly over parts
of north TX where some convective clustering may occur along a prior
outflow boundary and ahead of a weak MCV. Otherwise, see the
previous discussion for more information.
..Lyons.. 05/24/2026
.PREV DISCUSSION... /ISSUED 1141 AM CDT Sun May 24 2026/
...Middle Missouri Valley/Siouxland...
Limited/late-day-arriving forcing for ascent and modest-caliber
low-level moisture return by late May standards continues to temper
forecast confidence details. However, overall environment and
scenario appears to warrant a categorical Slight Risk centered on
Siouxland given some potential for supercells capable of large hail
later this afternoon through early/mid-evening.
A low-amplitude shortwave trough currently over Montana will
eventually influence the region, but generally not until this
evening. Low-level moisture will modestly increase but be offset by
diurnal mixing, near/east of a deepening surface low near the South
Dakota/Nebraska border vicinity. Low-level convergence will maximize
in this corridor, including northeast Nebraska/southeast South
Dakota/far northwest Iowa and at least isolated late-day storm
development is plausible, if not probable. If/where storms do occur,
upwards of 35-40 kt of effective shear associated with
west-northwesterly flow aloft would support supercells capable of
large hail in the presence of steep lapse rates and moderate
buoyancy. Additional and more elevated storm development over time
is expected farther north-northeast this evening into southern
Minnesota with some severe storms possible.
...Southeast States...
An MCV across Alabama will continue to spread east-northeastward and
influence thunderstorm development across Georgia toward South
Carolina and the southern Appalachians. The boundary layer will
continue to destabilize this afternoon and support the possibility
of isolated wind damage with the more robust storm development this
afternoon.
...North/central Texas...
Per visible satellite, ample insolation and heating of a moist
boundary layer will occur in the southern/eastern periphery of a
remnant mid-level low. While low/mid-tropospheric winds will remain
weak, sufficient heating and steep low-level lapse rates may support
some strong/locally severe pulse-type storms capable of downbursts,
and possibly a couple of instances of hail.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TSj12L
