RSS Mesoscale Discussions from Storm Prediction Center
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0804 PM CDT Tue Jun 09 2026
Valid 100100Z - 101200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL AND NORTHERN PLAINS...
...SUMMARY...
Numerous severe thunderstorms with a potential for 60-80 mph winds
with locally higher gusts, along with tornadoes (some potentially
strong), and large to very large hail are expected across the
northern and central Plains this evening into tonight.
...Central and Northern Plains...
On water vapor imagery, a mid-level shortwave trough appears to be
located from eastern Montana southeastward into western South Dakota
and west-central Nebraska. At the surface, a 996 mb low is currently
located in northwestern North Dakota with a cold front extending
southward from the low. A dryline is evident from central South
Dakota into western Nebraska. To the east of the front and dryline,
a moist airmass is in place with surface dewpoints in the mid to
upper 60s F, which is contributing to moderate to strong
instability. Thunderstorms are currently developing along the entire
length of the front and dryline. Storms that remain discrete or
semi-discrete over the next couple of hours could be supercells,
with a potential to produce tornadoes and large to very large hail.
A couple of strong tornadoes may occur with supercells that are
intense. As convective coverage rapidly increases over the next
couple of hours, a transition to linear mode is expected with a
squall line forming and moving eastward across the remainder of the
Dakotas this evening.
Along and near the instability axis, the RAP has 0-3 km lapse rates
in the 8 to 8.5 C/km range. In addition, 0-6 km shear near this axis
is around 45 knots, as is evident on the Bismarck and Aberdeen
WSR-88D VWPs. This environment will be very favorable for severe
wind gusts, and some gusts could exceed 80 mph along the more
intense parts of the line. While a tornado threat will exist with
supercells early on, a continued tornado threat is expected as the
squall line develops with embedded rotating cells. The potential for
severe wind gusts and tornadoes will continue into the late evening
and overnight period as the line moves eastward into the upper
Mississippi Valley.
Further south into the central Plains, the RAP has a pocket of
strong instability analyzed over east-central Nebraska, where the
RAP shows MLCAPE in the 4500 to 5500 J/kg range. Severe
thunderstorms have developed to the west and south of this
instability maximum. The RAP also has a 40 to 50 knot low-level jet
max in far northern Kansas. As this feature strengthens and moves
northeastward into eastern Nebraska, low-level shear will become
increasingly favorable for tornadoes. Supercells that can become
robust may be able to produce a strong tornado or two.
Southward into central Kansas, strong instability is analyzed by the
RAP over much of central and northeastern Kansas, where MLCAPE is
estimated to be from 3000 to 4500 J/kg. In addition, moderate
deep-layer shear is present and low to mid-level lapse rates are
steep. This will support a threat for large hail and severe wind
gusts this evening with the stronger supercells and short line
segments.
...Ohio Valley...
A moist and unstable airmass is currently located across much of the
Ohio Valley. An axis of instability is analyzed from southern
Illinois east-northeastward across southern Indiana and northwest
Ohio. Scattered thunderstorms are ongoing in west-central Indiana
just to the west of the instability axis. Ahead of the storms,
low-level lapse rates are steep. This will contribute to a potential
for isolated severe gusts over the next hour or two.
..Broyles.. 06/10/2026
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