863 

ACUS11 KWNS 151744
SWOMCD
SPC MCD 151744
PAZ000-NYZ000-OHZ000-MIZ000-INZ000-152015-

Mesoscale Discussion 0446
NWS Storm Prediction Center Norman OK
1244 PM CDT Wed Apr 15 2026

Areas affected...Parts of the southern Great Lakes region

Concerning...Severe potential...Watch possible

Valid 151744Z - 152015Z

Probability of Watch Issuance...60 percent

SUMMARY...The severe threat will gradually spread/develop eastward
through the afternoon, with the primary concerns being damaging wind
gusts and severe hail. A localized tornado risk is also possible,
though less certain.

DISCUSSION...The latest radar and satellite imagery show a remnant
MCV associated with an earlier convective complex tracking
east-northeastward across northern IN. This feature, along with
preceding weak low-level warm advection, should be the primary focus
for thunderstorms with eastward extent. Ahead of ongoing
thunderstorms accompanying the MCV, diurnal heating within cloud
breaks amid lower/middle 60s dewpoints is yielding marginal
destabilization of the downstream air mass. This, combined with
50-60 kt of midlevel west-southwesterly flow and elongated/mostly
straight hodographs (per regional VWP data), should favor a mix of
organized multicells and potentially a few supercells this
afternoon.

The limited large-scale forcing for ascent does cast uncertainty on
overall storm coverage and longevity, though current thinking is
that the potential for damaging wind gusts and severe hail will
increase with eastward extent. Additionally, locally boosted
low-level SRH along a remnant outflow boundary across northern OH
may support a slightly greater (albeit localized) tornado risk,
though this is uncertain. A watch may be needed this afternoon,
especially if ongoing storms continue to strengthen.

..Weinman/Gleason.. 04/15/2026

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

ATTN...WFO...BUF...CTP...PBZ...CLE...ILN...DTX...IWX...GRR...

LAT...LON   40328423 40378491 40538543 40928581 41428579 41838551
            42128500 42448404 42588291 42658201 42588027 42397960
            42017928 41287943 40878029 40638136 40328423

MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN