SPC MD 1905
MD 1905 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN ILLINOIS INTO NORTHERN INDIANA AND WESTERN OHIO

Mesoscale Discussion 1905
NWS Storm Prediction Center Norman OK
0515 PM CDT Mon Aug 10 2026

Areas affected...Northern Illinois into northern Indiana and western
Ohio

Concerning...Severe potential...Watch possible 

Valid 102215Z - 110015Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorm development is anticipated in the coming
hours across northern Indiana and western Ohio. Although timing
remains uncertain based on latest satellite trends, watch issuance
will likely be needed given a favorable convective environment for
severe thunderstorms.

DISCUSSION...Air mass recovery has been ongoing across IN and
western OH in the wake of convection earlier today with temperatures
warming well into the mid to upper 80s and dewpoints increasing into
the mid 70s. This low-level destabilization, combined with eastward
advection of steeper mid-level lapse rates, are supporting a
corridor of extreme buoyancy with MLCAPE values estimated to be
between 4000-5000 J/kg. 

Upstream, a subtle mid-level vorticity maximum is noted across
central IL has been supporting weak convection across northern IL
over the past few hours. Additional thunderstorm development appears
likely as ascent associated with this weak disturbance spreads east
towards the buoyancy axis. Although the region remains on the
southern periphery of a 40-50 knot mid-level jet, regional VWPs show
25-30 knot flow between 5-7 km, which is supporting adequate
hodograph elongation for effective bulk shear values on the order of
25-35 knots - sufficient for organized convection, including a few
supercells. 

Exact timing of when robust/intense convection develops remains
uncertain with latest GOES imagery showing limited vertical growth
of low-level cumulus. Additionally, recent high-res solutions also
shows disparity regarding the timing of convective initiation.
Regardless, watch issuance will likely be required once thunderstorm
initiation becomes apparent given the favorable convective
environment.

..Moore/Mosier.. 08/10/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...CLE...ILN...IWX...IND...LOT...

LAT...LON   41288866 41488898 41828925 42138914 42288889 42328840
            41648446 41508416 41268385 40988378 40198374 39848391
            39668419 39658459 41288866 

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN

Read more
https://www.spc.noaa.gov/products/md/md1905.html