RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0737 AM CDT Tue Apr 14 2026
Valid 141300Z - 151200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR IOWA INTO
THE SOUTHERN GREAT LAKES AND PORTIONS OF OKLAHOMA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
NORTHEAST...
...SUMMARY...
Severe thunderstorms are expected this afternoon through tonight
from the southern Plains into the Midwest. Large to giant hail,
several tornadoes (some strong), and severe gusts will be possible,
particularly from Iowa into the southern Great Lakes.
...Midwest...
An MCV near the IL-IN border this morning and southward-moving
outflow are linked to thunderstorms over parts of the eastern Corn
Belt. This outflow boundary will likely stall with the western
portion of the boundary advancing northward within a strengthening
warm conveyor this afternoon. Guidance generally depicts this
boundary stalling across eastern IA into southern WI by late
afternoon when daytime heating and ascent ahead of the upper wave
will erode inhibition and promote convective initiation along the
boundary. A moist airmass upstream over the lower MO Valley will
advect northeast beneath steep 700-500 mb lapse rates (reference the
12 UTC Topeka, KS raob). MLCAPE at or above 2500 J/kg is forecast
by mid-late afternoon from IA into the IA-WI-IL border vicinity.
Initial storms later this afternoon will rapidly become supercells
with all severe hazards possible. Large to giant hail and an
intense tornado will be possible with the more mature/strongest
supercells where SRH is locally maximized near the boundary.
Upscale growth into a severe cluster is forecast to eventually
evolve during the evening aided by a strong southwesterly LLJ into
the southern Great Lakes. If a supercell develops ahead of the
eastward-moving cluster, a tornado threat could develop as the
boundary layer quickly recovers/destabilizes.
...Kansas into Oklahoma and Texas...
Modest height falls across the central to southern Plains combined
with weak convergence along the dryline will likely support
scattered thunderstorms from eastern KS southward into western north
TX this afternoon into the evening. Aligning with earlier thinking,
strong heating and perhaps weak ascent tied to a subtle mid-level
wave, will favor storm development by 20-22z as convective
inhibition erodes. A very unstable airmass characterized by
2500-3000 J/kg MLCAPE and elongated hodographs will strongly favor
supercells. The strength of low-level shear remains unclear during
the early evening, when the tornado risk could maximize.
Nonetheless, increased confidence in widely scattered to scattered
supercells yielding a risk for large to giant hail prompted an
increase in hail and hail-intensity highlights this outlook update.
...Northeast...
A low-amplitude disturbance associated with an ongoing MCS near Lake
Ontario this morning will move east into the Northeast during the
day. Cloud breaks and low-level warm/moist advection will
contribute to a destabilizing airmass by midday. Veering and
strengthening winds with height will support storm organization,
including the potential for supercells. Eventually a band of storms
is forecast to evolve by mid-late afternoon with wind damage being
the primary risk. Have introduced low hail/tornado probabilities to
account for hazards associated with supercells.
..Smith/Dean.. 04/14/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0346 AM CDT Tue Apr 14 2026
Valid 171200Z - 221200Z
CORRECTED FOR DAY 5 GRAPHIC LABEL
...DISCUSSION...
...Day 4/Friday - Southern Plains to Upper Midwest...
A strong upper trough oriented from Montana to the Southwest will
eject eastward to the Plains on Friday/Friday night. Southwesterly
mid/upper flow will intensify ahead of this feature, with 40-60 kt
850-700 mb flow forecast by late afternoon into the nighttime hours.
A somewhat complex surface pattern is forecast, with a lee low
deepening over the central/southern High Plains to western OK, and a
second surface low near the Mid-Missouri Valley developing northeast
into Ontario. A surface dryline will extend from the High Plains low
to near the western OK/TX panhandle border into central TX by
midday. Meanwhile, a cold front will be oriented from eastern MN
into central KS at midday.
Ahead of these surface features, a broad warm sector characterized
by mid/upper 60s F dewpoints will be in place as temperatures warm
into the 80s F. A plume of steep midlevel lapse rates will
overspread the region, resulting in moderate to strong
destabilization. Forecast soundings indicated impressive wind
profiles supporting supercells. Initial supercell storms capable of
all hazards (including very large hail and strong tornadoes) are
expected. During the evening, convection may grow upscale into a
squall line as storms near the Mississippi River, with an
accompanying increase in damaging wind potential.
...Day 5/Saturday - Ohio Valley/Great Lakes vicinity...
A severe risk will likely continue into Saturday as the upper trough
continues to strengthen and shift east from the Plains to the Great
Lakes/Midwest. Strong deep-layer flow parallel to an
eastward-advancing cold front will overspread a moist and at least
weakly unstable downstream airmass through evening. This will favor
a line of convection with damaging wind potential.
...Days 6-8/Sunday-Tuesday...
The surface cold front will continue east on Sunday, moving offshore
the Atlantic and Gulf coasts during the afternoon. Severe potential
appears limited by weak instability and mainly anafrontal
precipitation across the Southeast to Eastern U.S. on Sunday.
Surface high pressure and a dearth of boundary layer moisture in the
wake of the cold front will preclude thunderstorm activity on
Monday. By the end of the period, medium range guidance depicts
another upper trough moving into the western U.S. and Gulf return
flow will advect moisture back into the southern Plains. However,
severe thunderstorm potential appears low at this time.
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