RSS Mesoscale Discussions from Storm Prediction Center
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Wed May 13 2026
Valid 151200Z - 161200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN KANSAS AND NORTHERN MISSOURI...
...SUMMARY...
Severe storms with large hail and severe wind gusts will be possible
on Friday in parts of the central Plains and lower Missouri Valley.
...Southern and Central Plains/Lower Missouri and mid Mississippi
Valleys...
Mid-level flow will be westerly over the central U.S. on Friday.
Within the flow, a subtle shortwave trough is forecast to move
across the central Plains. At the surface, low-level moisture
advection will result in a pocket of moist air from the central
Plains eastward into the lower Missouri Valley, where surface
dewpoints are forecast to be in the mid to upper 60s F. Within this
moist airmass, moderate instability is expected to be in place by
afternoon. A dryline is forecast to develop on the western edge of
the low-level moisture, from north-central Oklahoma into central
Kansas. Isolated to scattered thunderstorms are expected to form to
the east of the dryline during the late afternoon and early evening.
Additional storms are expected to form further east into eastern
Kansas and Missouri, along the northern edge of a low-level jet.
Late Friday afternoon, forecast soundings in the Kansas City area
show a favorable thermodynamic environment for severe storms. MLCAPE
is forecast to be in the 3000 to 4000 J/kg range with 700-500 mb
lapse rates near 8 C/km. In addition, 0-6 km shear is forecast to be
in the 30 to 35 knot range. This environment will be favorable for
supercells with large hail and wind damage. An isolated severe
threat may also develop eastward into the mid Mississippi Valley and
southwestward into north-central Oklahoma. Instability is expected
to be somewhat weaker in these two areas, which should keep any
severe threat more isolated and marginal.
..Broyles.. 05/13/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0357 AM CDT Wed May 13 2026
Valid 161200Z - 211200Z
...DISCUSSION...
...Saturday/Day 4 to Monday/Day 6...
At mid-levels, a shortware trough will move eastward across the
western U.S. on Saturday, as flow becomes west-southwesterly over
much of the central U.S. In response, moisture advection is forecast
to increase over the central U.S. as a pocket of 65 to 70 F
dewpoints moves northward into the lower and mid Missouri Valley. A
dryline is forecast on the western edge of the moist airmass.
Isolated to scattered storms appear likely to initiate to the east
of the dryline in the afternoon. Additional storms may form eastward
across the lower to mid Missouri Valley. Moderate deep-layer shear
is forecast over the instability axis, which should support a
potential for supercells with large hail and severe wind gusts.
On Sunday, an upper-level trough is forecast to develop over the
western U.S. Mid-level flow is expected to become southwesterly over
the Great Plains, where model forecasts show a surge of low-level
moisture. In response, surface dewpoints are forecast to increase
into the mid to upper 60s F over much of the north-central U.S. A
series of subtle shortwave troughs moving through the Great Plains
will likely support scattered to numerous thunderstorms in the
afternoon and evening. The greatest severe threat may develop over
eastern Nebraska and western Iowa, along the northern edge of a
low-level jet. A potential for supercells with large hail, wind
damage and a tornado threat is expected.
On Monday, the upper-level trough is forecast to move across the
Intermountain West, as multiple shortwave impulses move
northeastward across the Great Plains. A cold front is forecast to
move southeastward across the central U.S. Ahead of the front,
surface dewpoints in the lower to mid 70s F are forecast to be in
place by afternoon. In response, strong instability is expected to
develop in parts of the moist airmass. In addition, a mid-level jet
is forecast to eject northeastward across the central U.S. Moderate
to strong deep-layer shear associated with the jet will support a
potential for severe storms across a broad area from the southern
Plains northeastward into the Upper Midwest. Supercells and bowing
line segments with large hail, severe wind gusts and tornadoes will
be possible.
...Tuesday/Day 7 and Wednesday/Day 8...
On Tuesday and Wednesday, a cold front is forecast to move from the
Upper Midwest southeastward into the Appalachians. A moist and
unstable airmass will likely be in place ahead of the front, with
scattered to numerous thunderstorms likely developing each afternoon
and evening. The greatest severe threat could materialize over the
mid Mississippi and lower Ohio Valley on Tuesday, and in the
Northeast on Wednesday, adjacent to a mid-level jet passing through.
However, uncertainty is substantial at this time concerning the
timing of the upper-level trough and cold front.
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