RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Mar 10 12:36:02 UTC 2026.
No Mesoscale Discussions are in effect as of Tue Mar 10 12:36:02 UTC 2026.
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0733 AM CDT Tue Mar 10 2026
Valid 101300Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE MID
MISSISSIPPI VALLEY INTO THE SOUTHERN GREAT LAKES...AND FROM WEST
TEXAS INTO SOUTHWEST OKLAHOMA...
...SUMMARY...
Severe thunderstorms are forecast today from the southern Plains
into the southern Great Lakes vicinity. All severe hazards are
possible, including the risk for a few strong to intense tornadoes
and very large hail.
...Synopsis...
A split-flow upper pattern persists across the CONUS this morning.
Early-morning satellite imagery shows a well-defined upper low over
the central Baja Peninsula within the southern stream and a subtle,
low-amplitude shortwave trough moving through the Pacific Northwest
within the northern stream. Surface analysis shows a large reservoir
of low-level moisture from the southern Plains and Lower MS Valley
northeastward into the southern Great Lakes. General expectation is
for both the southern-stream upper low and northern-stream shortwave
to progress eastward today, as some modest phasing occurs between
these two features.
This evolution will contribute to strengthening mid-level flow
across much of the Plains and MS Valley, while also resulting in
increased ascent across the broad warm sector. This will result in a
large area of strong to severe thunderstorms from the southern
Plains into the southern Great Lakes, beginning during the early
afternoon and persisting through the evening and overnight. Two
areas within this broader region, west TX into southwest OK and the
Mid MS Valley into the southern Great Lakes, have environmental
conditions that support the potential for significant severe
weather, including very large hail greater than 2" in diameter and
strong to intense tornadoes.
...Mid MS Valley into the Southern Great Lakes...
Northern-stream shortwave trough is forecast to move out of MT/WY
this evening, accompanied by strong mid-level flow (over 100 kt at
500 mb). However, this will be well west of the moist and buoyant
airmass across the Mid MS Valley. Even so, modest height falls are
anticipated over the region beginning during the late afternoon. Of
more consequence for the severe-weather potential, a surface low
(currently over the central NE/KS border vicinity) will eject
northeastward ahead of the shortwave, moving along the stationary
boundary that currently extends into far southern WI. This boundary
is also expected to sharpen throughout the day as low-level moisture
advection persists to its south and cold, northeasterly surface
winds persist to its north. Low-level convergence near the surface
low and stationary front will be augmented by the previously
mentioned subtle height falls to support thunderstorm development.
These mesoscale details as well as which side of the stationary
boundary storms develop will be key for determining the primary
severe hazard.
The airmass south of the stationary front is expected to be
moderately to strongly unstable, as temperatures in the 80s,
dewpoints in the low/mid 60s, and steep mid-level lapse rates
combine to support 2000+ J/kg of MLCAPE. Steep mid-level lapse rates
and associated moderate elevated buoyancy will persist north of the
front as well. Given the subtle forcing and mesoscale character of
this set up, CAM guidance varies notably on the timing and location
of thunderstorm development.
Kinematic profiles suggest that any surface-based warm sector
development should quickly become supercellular, with all severe
hazards possible, including very large hail and tornadoes. A strong
to intense tornado is possible, particularly with any storms ongoing
around 00Z when the low-level flow increases notably, resulting in
considerable elongation of the low-level hodograph. Latest guidance
suggests this tornado risk will exist into parts of far southwest
Lower MI, so probabilities were expanded accordingly. Very large
hail (i.e. 2"+ in diameter) will also be possible north of the front
where strong deep-layer vertical shear exists.
...Southern Plains...
The southern-stream upper low is forecast to eject eastward across
northern Mexico today, with ascent preceding this low overspreading
a West TX dryline by the afternoon. Initial storm development is
anticipated over the Permian Basin/Big Bend vicinity, with moderate
buoyancy and very strong vertical shear supporting a quick evolution
into supercells capable of very large hail greater than 3" in
diameter. Increasing thunderstorm coverage is expected from
southwest TX into southwest OK as the upper low continues eastward.
Very large hail will remain the primary severe risk although a trend
towards a more linear mode is expected throughout the evening.
Strong gusts could accompany the resulting squall line. The tornado
risk is expected to remain low, owing primarily to the modest
low-level flow. This low-level flow is expected to increase across
the TX Hill Country tonight, where a relatively greater tornado risk
could materialize if cells remain discrete.
...Northern OK/KS into the Lower OH Valley...
Most guidance has trended towards greater thunderstorm coverage
tonight near the front across northern OK and KS. Moderate buoyancy
and shear will be in place, supporting strong to severe
thunderstorms. Large to isolated very large hail is possible with
the initial development before a trend towards a linear mode shifts
the primary hazard to damaging gusts. The resulting convective line
is then expected to continue eastward across AR and MO before
reaching the Lower OH Valley early tomorrow morning. Damaging gusts
will remain possible as the line moves east overnight. A
low-probability tornado threat could also exist within this line as
it moves into the greater low-level moisture and stronger low-level
flow farther east across central/southern MO and far southern IL.
..Mosier/Dean.. 03/10/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0247 AM CDT Tue Mar 10 2026
Valid 131200Z - 181200Z
...DISCUSSION...
Severe thunderstorm potential will remain low on Days 4-5/Fri-Sat as
a cold frontal passage and surface high pressure over the central
U.S. leave a dry/stable airmass across much of the CONUS east of the
Rockies.
On Saturday, lower-amplitude, quasi-zonal flow over much of the U.S.
will amplify as a shortwave upper trough deepens over the Rockies
and emerges over the High Plains by Day 6/Sunday morning. As this
occurs, modest Gulf moisture will return northward across east TX
into the Mid-South. A strong surface low is forecast to move across
the Upper Midwest on Sunday as the upper trough continues to dig and
shift east into the Midwest. This will bring a cold front southeast
across portions of the Plains and Midwest. Some severe potential
could develop across central portions of the U.S. on Day 6/Sunday as
the cold front sweeps eastward, but confidence is low given a lack
of deeper moisture return overlapping with stronger shear across the
Midwest.
As the upper trough and surface cold front continue east on Day
7/Monday, some low-end severe potential could possibly develop
across the Mid-Atlantic to the Southeast, but confidence is low
given similar concerns to those on Day 6/Sunday. With this system
moving offshore by the end of the period, severe potential appears
low on Day 8/Tuesday.
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