RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 AM CDT Sat May 23 2026
Valid 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN PLAINS...WESTERN AND CENTRAL GULF COAST...FROM GEORGIA
INTO SOUTH CAROLINA...AND ACROSS OHIO...
...SUMMARY...
Thunderstorms with isolated severe wind gusts and hail will be
possible this afternoon and evening across parts of the southern
Plains. A few strong wind gusts and an isolated tornado threat will
be possible from southeast Texas into southern Louisiana. A few
strong gusts may also occur from Georgia into South Carolina. An
isolated tornado threat is also expected in parts of Ohio.
...Southern High Plains...
An upper-level trough will move eastward today across the Great
Plains. At the surface, a broad moist sector will be in place across
the southern Plains where dewpoints will be mostly in the 60s F. In
response, an axis of moderate instability will develop by afternoon
from the Texas Panhandle southward into west Texas. Scattered
thunderstorms are expected to form during the mid to late afternoon
near this axis of instability. RAP forecast soundings in the Texas
Panhandle in the late afternoon have MLCAPE near 1500 J/kg and 0-6
km shear in the 25 to 35 knot range, with 700-500 mb lapse rates
around 8 C/km. This should support a marginal severe threat.
Isolated large hail and a few strong wind gusts will be possible.
...South-central and Southeast Texas/Southern Louisiana...
In the coastal areas of the western and central Gulf, very moist air
will be in place. Surface dewpoints in the lower to mid 70s F will
contribute to moderate instability by midday. Thunderstorms will
form along sea breeze boundaries during the early to mid afternoon.
A few severe wind gusts and a brief tornado will be possible.
Further west into parts of south-central Texas, moderate to strong
instability is forecast by afternoon with MLCAPE peaking in the 2500
to 3500 J/kg range. This, combined with moderate deep-layer shear,
may support isolated severe storm development this afternoon. The
primary threats would be for hail and isolated severe wind gusts.
...Georgia/South Carolina...
A mid-level shortwave trough will move across the Southeast today.
At the surface, moist air will be in place from the Gulf Coast
states into the Carolinas, where moderate instability will develop
by midday. During the afternoon, scattered thunderstorms will form
from Georgia into South Carolina. As instability increases during
the day, low-level lapse rates will become steep. This should be
sufficient for an isolated potential for severe wind gusts.
...Ohio...
Southwesterly mid-level flow will be in place over the Ohio Valley
and lower Great Lakes today. At the surface, an axis of low-level
moisture will be located from eastern Kentucky into central and
northern Ohio, where dewpoints will be in the mid to upper 60s F. As
instability increases during the day, scattered thunderstorms are
expected to develop and move northeastward across the instability
corridor. RAP forecast soundings in central Ohio at 21Z have 0-6 km
shear near 30 knots with 0-3 km storm-relative helicity around 150
m2/s2. This could be enough for an isolated tornado threat.
..Broyles/Chalmers.. 05/23/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1253 AM CDT Sat May 23 2026
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
NEBRASKA INTO SOUTHWEST MINNESOTA...
...SUMMARY...
Widely scattered thunderstorm activity will be possible from the
southern/central Plains to the southeastern US into the lower Ohio
Valley. A few stronger storms may be possible from central Nebraska
into southwest Minnesota.
...Synopsis...
Widely scattered afternoon thunderstorms are likely south of a
stationary front extending from the southern Plains into the lower
Ohio Valley. A few additional thunderstorms will be possible across
the southern High Plains within the easterly upslope regime. A weak
shortwave trough will move across the central/northern Plains into
the Upper Midwest on D2/Sunday, which may be a focus of thunderstorm
development across portions of Nebraska into Minnesota. Large hail
and damaging wind will be the primary threat with these storms.
...Nebraska into Minnesota...
A plume of mid 50s to 60s dew points will advect northward into
portions of eastern Nebraska into southern Minnesota Sunday
afternoon amid increasing southerly flow across the central/northern
Plains. A weak shortwave will move eastward across this area with
thunderstorm development likely by the afternoon. Forecast soundings
suggest that deep layer shear will be sufficient to support
supercells, with around 40 kts in the 0-6 km layer. In addition to
the increase in moisture, steep low to mid-level lapse rates will
also overspread the area. This, in combination with strong deep
layer shear, will favor potential for large hail (isolated very
large hail up to 2" in diameter). Well mixed profiles may also
support a few instances of strong to severe wind.
..Thornton.. 05/23/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0217 AM CDT Sat May 23 2026
Valid 251200Z - 261200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Scattered thunderstorms will be possible from portions of the
Southwest to the central/southern High Plains and across the
southern Ohio Valley and the Southeast. Additional shower and
thunderstorm activity will be possible across the Pacific Northwest.
Severe storms are generally not expected.
On D3/Monday, guidance suggests that height rises will begin across
the central US as a high amplitude ridge builds in from the west. An
upper level low will begin to deepen and move inland across the
Pacific Northwest through the period. Though instability will be
minimal, cooling temperatures aloft with the upper low may promote a
few thunderstorms towards the end of the period.
Slow moisture return will continue across much of the Plains into
the Midwest, with areas of widely scattered areas of thunderstorms
possible across portions of the Southwest to the southern/central
High Plains and from the southern Ohio Valley into the Southeast. A
few strong to marginally severe storms will be possible from the
Plains to the Southeast where better instability resides, but
generally weak flow and subsidence aloft will keep organized storm
potential low.
..Thornton.. 05/23/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0353 AM CDT Sat May 23 2026
Valid 261200Z - 311200Z
...DISCUSSION...
A trough will deepen and shift eastward across the Pacific Northwest
D4/Tuesday-D5/Wednesday. As the upper low slowly shifts eastward,
stronger flow will overspread the Intermountain West into the
Northern Rockies which will result in strengthening lee troughing
across the central/northern Plains. Moisture advection will spread
northward with the strengthening southerly flow across the
central/northern Plains. Severe storms may occur each day across
some portion of the northern and northern/central High Plains. In
addition, strengthening southern stream flow may bring stronger
storms across the Sierra Madre which may bring severe potential into
portions of far southern Texas. For now, confidence in exact
corridors of greater severe potential remains low.
By D6/Thursday-D8/Saturday, guidance suggests the western low
becomes cut off and slowly wobbles towards the Great Basin before
becoming absorbed back into the northern stream, likely due to the
high amplitude ridging across the central. Some severe potential may
extend into the eastern US as a cold front shifts southward as flow
enhances in the trough across Quebec in the D6-D7 period.
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