Mesoscale Discussion 0210
NWS Storm Prediction Center Norman OK
0423 AM CDT Wed Mar 11 2026
Areas affected...Parts of central/southern IL...central IN...western
OH
Concerning...Severe potential...Watch possible
Valid 110923Z - 111130Z
Probability of Watch Issuance...40 percent
SUMMARY...The severe threat may gradually increase through dawn.
Trends will be monitored for possible watch issuance.
DISCUSSION...Multiple bands of generally disorganized convection are
moving across parts of central IN this morning, to the
east/southeast of a surface low currently centered over northeast
IL/northwest IN. The northern extent of surface-based instability is
constrained by an outflow-reinforced front across northern IN/OH,
but convection has recently developed south of this front, where
MLCAPE of 1000-1500 J/kg and strong unidirectional southwesterly
flow are in place early this morning. In the short-term, some
lingering surface-based CINH and only modest large-scale ascent may
mitigate potential for storms to mature and become organized within
the otherwise favorable environment. However, some increase in the
potential for more organized fast-moving cells/clusters is expected
with time through the morning, which may eventually result in a
threat for localized damaging wind, isolated hail, and possibly a
tornado.
Farther west, a long-lived bowing segment is moving across
west-central IL, to the east of St. Louis. This bowing segment
recently produced a wind gust to 58 kt in Alton, IL (KALN), though
other observed gusts have generally been in the 40-45 kt range.
Notable downstream pressure falls and a seasonably warm/moist
boundary layer may help to sustain this bowing segment through dawn.
With strong southwesterly low-level flow in place along with
favorable deep-layer shear, this bowing segment may continue to pose
a threat of locally damaging wind and possibly a tornado, as it
moves east-northeastward near and south of the outflow-reinforced
baroclinic zone.
The magnitude and coverage of the severe threat across the region
through dawn remain uncertain, but given the conditionally favorable
environment, watch issuance is possible if trends support an uptick
in storm organization.
..Dean/Mosier.. 03/11/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CLE...ILN...IWX...IND...PAH...ILX...LSX...
LAT...LON 39148596 37838948 38479004 39748930 40328726 41078554
41198520 41288393 41228291 40828281 40318299 39848388
39598478 39148596
MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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