RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1106 AM CDT Fri Apr 03 2026
Valid 031630Z - 041200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING OVER PARTS OF SOUTHERN IOWA...NORTHERN MISSOURI...AND
WESTERN ILLINOIS....
...SUMMARY...
Thunderstorms are expected to evolve into an extensive line this
evening from Iowa to Oklahoma and northwest Texas, with the primary
threats of large hail and damaging winds. A few tornadoes are also
possible in any supercells that can form ahead of the line over
parts of Iowa, Missouri, and central Illinois.
...MO/IA/IL...
Latest surface analysis shows a low over northeast KS. This low
will track northeastward across southern IA today, with the
associated warm front lifting northward into northern IL. The air
mass in the warm sector of the low will be relatively moist and
unstable with dewpoints in the lower 60s and afternoon MLCAPE values
of 2000 J/kg. Thunderstorms are expected to develop near the
surface low in IA, and more widely scattered storms eastward along
the warm front. A few supercells are possible across this region,
with a concern for tornadoes, large hail, and damaging winds in the
most intense cells.
...MO/KS/OK/TX...
An extensive line of thunderstorms is expected to form along the
cold front this afternoon from western MO into southeast KS and much
of OK. Ample low-level moisture and CAPE will be present ahead of
the storms, along with sufficient deep-layer shear for
rotating/bowing storm structures. Large hail and damaging winds
appear to be the main concern, but a tornado or two are also
possible.
..Hart/Wendt.. 04/03/2026
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0254 PM CDT Fri Apr 03 2026
Valid 032000Z - 041200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHERN IOWA...NORTHERN MISSOURI AND WESTERN ILLINOIS....
...SUMMARY...
Thunderstorms are expected to evolve into an extensive line this
evening from Iowa to Oklahoma and northwest Texas, with the primary
threats of large hail and damaging winds. A few tornadoes are also
possible in any supercells that can form ahead of the line over
parts of Iowa, Missouri, and central Illinois.
...20z update KS, MO IA and IL...
Scattered thunderstorm development was ongoing this afternoon ahead
of a weak surface low an associated cold front over the MO Valley.
To the east, a broad and unstable warm sector exists south of a
quasi-stationary front extending into eastern MO and IL. Moderate
buoyancy and deep-layer shear will support a mix of supercells.
Damaging winds and hail remain the most likely near the cold front
as it moves eastward with a linear storm modes. A few tornadoes are
also possible with more discrete cells and backed surface winds
along the warm front farther east. The primary update to the
forecast was to remove thunder and severe probabilities behind the
cold front, otherwise the severe risk remains as is.
...Southern KS, OK and into TX...
Scattered to numerous thunderstorms remain likely this afternoon and
evening along the advancing cold front from southern KS, across much
of OK and ahead of a dryline into west-central TX. South of the
primary upper trough and stronger flow aloft, overall forcing will
be weaker. Still, forecast soundings and observation trends show
moderate destabilization and sufficient deep-layer shear for
supercells and organized clusters/line segments. Hail (some 2+ in)
is possible with initial supercells before upscale growth is
expected to take place with the surging cold front.
A locally more favorable zone for large hail, damaging gusts and a
tornado or two may develop across parts of central and southern OK
if semi discrete supercells or stronger bowing structures can become
organized/maintained this afternoon/evening.
...OH Valley...
A moist and unstable air mass will support scattered thunderstorms
across the OH valley this afternoon. Isolated damaging gusts are
possible with multi-cell storms/clusters amid modest vertical shear.
Storms should weaken this evening with the loss of diurnal heating.
..Lyons.. 04/03/2026
.PREV DISCUSSION... /ISSUED 1106 AM CDT Fri Apr 03 2026/
...MO/IA/IL...
Latest surface analysis shows a low over northeast KS. This low
will track northeastward across southern IA today, with the
associated warm front lifting northward into northern IL. The air
mass in the warm sector of the low will be relatively moist and
unstable with dewpoints in the lower 60s and afternoon MLCAPE values
of 2000 J/kg. Thunderstorms are expected to develop near the
surface low in IA, and more widely scattered storms eastward along
the warm front. A few supercells are possible across this region,
with a concern for tornadoes, large hail, and damaging winds in the
most intense cells.
...MO/KS/OK/TX...
An extensive line of thunderstorms is expected to form along the
cold front this afternoon from western MO into southeast KS and much
of OK. Ample low-level moisture and CAPE will be present ahead of
the storms, along with sufficient deep-layer shear for
rotating/bowing storm structures. Large hail and damaging winds
appear to be the main concern, but a tornado or two are also
possible.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
1245 PM CDT Fri Apr 03 2026
Valid 041200Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY AFTERNOON
AND EVENING ACROSS PARTS OF SOUTHEASTERN INDIANA...NORTHERN
KENTUCKY...MUCH OF OHIO...SOUTHEASTERN LOWER MICHIGAN...WESTERN
PENNSYLVANIA AND NEW YORK...
CORRECTED FOR WORDING AND TYPOS
...SUMMARY...
Severe thunderstorms may develop and overspread the lower Great
Lakes vicinity and middle through upper Ohio Valley Saturday
afternoon and evening, accompanied by strong to severe wind gusts
and potential for a couple of tornadoes.
...Discussion...
As mid-level ridging builds further across the British Columbia and
Pacific Northwest vicinity Saturday through Saturday night, models
indicate that several digging downstream short wave troughs across
the Canadian Prairies into the northern U.S. Great Plains may
contribute to the northeastward acceleration of a notable mid-level
low, now slowly turning eastward toward the middle Missouri Valley.
In response to these developments, an initially modest surface
cyclone associated with the lead perturbation is generally forecast
to undergo substantive deepening while occluding across and
northeast of the upper Great Lakes vicinity. A secondary cyclone
may form across the southeastern Michigan through Lake
Huron/Georgian Bay/adjacent Ontario vicinity by Saturday afternoon,
with a trailing cold front continuing to advance east of the
Mississippi Valley and southward through the southern Great Plains,
into the Appalachians/lower Mississippi Valley/northwest Gulf coast
vicinity by early Sunday.
Initially cold, stable air to the north of a preceding front may
remain entrenched across much of New England through this period,
while widespread thunderstorm development today through tonight cuts
off the advection of elevated mixed-layer air and associated steeper
mid-level lapse rates to the east of the Mississippi Valley. At the
same time, the impact of lingering pre-frontal convective
development, associated surface outflow and northeastward/eastward
advecting remnant cloud cover on subsequent destabilization within a
potentially expanding warm sector across the mid/upper Ohio Valley
and lower Great Lakes region remains unclear.
...Ohio Valley into lower Great Lakes region...
Conditionally, a relatively moist (60+ F surface dew points) air
mass within the evolving warm sector is likely to become conducive
to organized severe thunderstorm development, including supercells,
Saturday afternoon and evening. However, stronger mid/upper support
for ascent may remain displaced to the northwest of much of the
destabilizing warm sector, with strongest forcing for convection
confined to the front, or, perhaps more likely, a conglomerate
pre-frontal outflow.
Although the signal in model output is not particularly strong, it
appears possible that convection may begin re-intensifying along the
leading outflow boundary while overspreading southeastern Lower
Michigan into the lower Ohio Valley by early afternoon. As this
occurs, strong lower/mid-tropospheric shear beneath south to
southwesterly wind fields strengthening to 40-60+ kt in the 850-500
mb layer will be more than sufficient to support organization and
increasing risk for severe wind gusts and tornadoes. This threat
likely will persist as activity overspreads much of the remainder of
the Ohio Valley and lower Great Lakes region into Saturday evening.
...Parts of the Mid South into northwestern Gulf Coast...
Weaker mid/upper forcing for ascent, deep-layer mean wind field and
shear suggest more limited severe weather potential than further
north. However, somewhat better boundary-layer moisture, including
mid 60s F+ dew points, may contribute moderate CAPE ahead of
southeastward advancing convective outflow. It appears possible
that this could support re-intensification of convection that could
become accompanied by sporadic damaging downbursts late Saturday
afternoon into evening.
..Kerr.. 04/03/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 PM CDT Fri Apr 03 2026
Valid 051200Z - 061200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY ACROSS
PARTS OF THE SOUTHERN MID ATLANTIC COAST...
...SUMMARY...
Strong thunderstorms may impact parts of the southern Mid Atlantic
Coast vicinity Sunday, accompanied by at least some risk for
damaging wind gusts.
...Discussion...
Latest model output suggests that a broad, deep occluded surface
cyclone may deepen at least a bit further while migrating
east-northeastward across Quebec during this period. Renewed
cyclogenesis appears possible across the Canadian Maritimes by
Sunday evening, with a trailing cold front advancing offshore of the
northern through middle Atlantic coast by early Monday, while
slowing/stalling across parts of northern Florida.
Pre-frontal boundary-layer destabilization, where deep-layer mean
flow and shear appears sufficient to support convective
organization, is forecast to remain weak, due to generally weak
tropospheric lapse rates. It appears that this may become focused
along lee surface troughing across and east of the Carolina
Piedmont, perhaps as far north as a developing low/frontal wave
across south central Virginia into the southern Delmarva Peninsula
by late Sunday afternoon.
Forcing for ascent, downstream of a short wave impulse progressing
through the base of approaching larger-scale mid-level troughing, is
likely to aid convective development, with sheared, 30-50 kt
south-southwesterly flow in the 850-500 mb layer contributing
convective organization with potential to produce damaging wind
gusts. A narrow broken squall line may evolve, with perhaps
embedded supercell structures which could also pose the risk for a
tornado or two while spreading toward coastal areas by early Sunday
evening.
..Kerr.. 04/03/2026
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