RSS Mesoscale Discussions from Storm Prediction Center
SPC 2000Z Day 1 Outlook
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.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 PM CDT Sun May 24 2026
Valid 251200Z - 261200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE MN
ARROWHEAD REGION...PARTS OF THE CENTRAL PLAINS AND MIDWEST...PARTS
OF NM/FAR WEST TX...AND PARTS OF THE SOUTHEAST...
...SUMMARY...
Isolated strong to severe storms will be possible across parts of
the Minnesota Arrowhead region, central Plains and Midwest,
Southeast, and New Mexico/Far West Texas on Monday.
...MN Arrowhead region...
While large-scale ascent will be nebulous at best amidst modest
midlevel height rises, most guidance depicts strong heating and
potential for at least isolated storm development in the vicinity of
a cold front across parts of MN Arrowhead region during the
afternoon. Deep-layer flow will be modest, but southwesterly surface
winds veering to west-northwesterly aloft will result in 30-35 kt of
effective shear, sufficient for storm organization. Relatively steep
lapse rates and moderate buoyancy will support isolated hail and
localized strong/damaging gusts, if storms can mature across this
region.
...Central Plains into southwest MN/northwest IA...
While forcing will generally be weak, strong diurnal heating may
support isolated storm development in the vicinity of a weak surface
trough/confluence zone from northern NE/southern SD into northwest
IA/southwest MN. Deep-layer flow will be weak, but modest midlevel
west-northwesterlies may provide sufficient deep-layer shear for
some storm organization. Favorable lapse rates and buoyancy will
support potential for isolated hail and localized damaging gusts.
...NM into Far West Texas...
Relatively widespread convection is expected on Monday across parts
of NM into Far West TX, in association with mid/upper-level trough
over the Southwest. Buoyancy is expected to remain relatively modest
across NM, but generally unidirectional southerly flow within a
relatively well-mixed environment will support outflow-driven
clusters capable of localized severe gusts. Strong storms may spread
into parts of Far West TX Monday night, with a continued threat of
strong to localized severe gusts.
...Southeast...
A similar regime to previous days is expected across the Gulf
Coast/Southeast, with widespread convection expected to the east of
a persistent mid/upper-level trough over east TX. Water-loaded
downdrafts will again be capable producing localized wind damage,
with any more organized potential tied to uncertain MCV development.
A Marginal Risk has been included from the FL Panhandle into GA,
where there appears to be the greatest potential for preconvective
heating/destabilization. If organized MCV development occurs, then
there may be some severe potential to the west and north of this
Marginal Risk area.
...Interior Northwest/Northern Rockies...
Thunderstorm development is expected by afternoon from far eastern
OR/WA into ID/western MT/northwest WY, in advance of a vigorous
mid/upper-level shortwave trough moving into the Pacific Northwest.
Much of this activity may be relatively high-based and disorganized,
with strong outflow gusts possible. The most aggressive guidance
regarding moistening and destabilization suggests some marginal
supercell potential across northern ID and far western MT. Severe
probabilities may eventually be needed across parts of the region,
if guidance consensus trends towards a greater potential for
organized convection.
..Dean.. 05/24/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0222 PM CDT Sun May 24 2026
Valid 261200Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHWEST TEXAS...
...SUMMARY...
Scattered severe storms will be possible across western Texas into
southeastern New Mexico Tuesday afternoon and evening. Across this
region, large hail, severe gusts, and perhaps a tornado will be
possible.
...Parts of west TX and southeast NM...
No major changes have been made to the Slight Risk area. A broad
negative-tilt mid/upper trough with multiple embedded vorticity
maxima will impinge upon relatively rich moisture and moderate to
locally strong buoyancy across parts of west TX and southeast NM on
Tuesday. Weak capping and increasingly difluent flow aloft will
likely lead to multiple rounds of thunderstorms through the day and
into Tuesday night. Low-level southeasterly flow veering to modest
southwesterlies aloft will result in 30-40 kt of effective shear,
supporting potential for organized clusters and a few supercells.
Large hail and localized severe gusts could accompany the strongest
storms. Gradually increasing low-level shear/SRH could also support
some tornado threat from afternoon into the evening.
Convection could spread into a larger portion of south-central TX by
Tuesday night, though decreasing shear and increasing low-level
stability with eastward extent should lead to an eventual weakening
trend. The Marginal Risk was expanded eastward somewhat to account
for isolated severe potential into late evening.
...Central/western MT and adjacent parts of northern ID...
Scattered thunderstorms are expected during the day/evening from
parts of northern ID into western/central MT, in association with a
mid/upper-level low/trough over the Pacific Northwest. Moisture and
instability will likely remain modest at best, but increasing
deep-layer shear could support a few strong storms, with a threat of
localized severe gusts and marginally severe hail.
..Dean.. 05/24/2026
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