Mesoscale Discussion 1943
NWS Storm Prediction Center Norman OK
1004 PM CDT Tue Aug 11 2026
Areas affected...Central Wisconsin
Concerning...Severe potential...Watch unlikely
Valid 120304Z - 120500Z
Probability of Watch Issuance...20 percent
SUMMARY...Percolating cumulus is being monitored for deep convective
initiation across central Wisconsin. While it is unclear if
thunderstorms will develop, the regional environment is
conditionally supportive of strong/severe thunderstorms.
DISCUSSION...Over the past 30 minutes, deepening cumulus has been
noted in GOES IR imagery along a surface trough/confluence zone
across central WI. Earlier attempts at convective initiation have
been noted further west across southeast MN and western WI as a
subtle mid-level wave traverses northern IA. It is unclear if this
more recent development is associated with this mid-level feature or
weak ascent along the confluence zone (or a combination of both).
Regardless, the recent 00 UTC MPX sounding sampled rich low-level
moisture on the warm side of the boundary, and steep mid-level lapse
rates with MLCAPE values just under 3000 J/kg. Accounting for drier
and cooler conditions across WI suggests that buoyancy is somewhat
more limited, but still supportive of deep convection. Additionally,
50 knot flow aloft coupled with weak low-level winds hints that
hodographs will be sufficiently elongated to support organized
convection, including the potential for supercells.
Despite the conditionally supportive environment, it is unclear if
ascent will be sufficient to initiate and sustain deep convection.
Earlier failed attempts suggest ascent is too meager, and recent
HRRR/RRFS solutions have been trending towards more limited
thunderstorm coverage with successive runs. Consequently, confidence
in a robust/widespread severe threat is limited. Nonetheless,
convective trends will continue to be monitored given the number of
candidate updrafts emerging in IR imagery.
..Moore/Mosier.. 08/12/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MQT...GRB...ARX...MPX...
LAT...LON 44949179 45299018 45368883 45348811 45278770 45088740
44888733 44538740 44228749 44108776 44078824 44098893
44129017 44169077 44249131 44389172 44549193 44799205
44949179
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
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