Mesoscale Discussion 0317
NWS Storm Prediction Center Norman OK
1206 PM CDT Wed Apr 01 2026
Areas affected...Parts of middle/upper Ohio Valley
Concerning...Severe potential...Watch possible
Valid 011706Z - 011900Z
Probability of Watch Issuance...40 percent
SUMMARY...A general increase in storm coverage and intensity is
expected within a moist airmass in the middle/upper Ohio Valley this
afternoon. Damaging winds are the main hazard along with more
limited potential for a tornado or large hail. Storm coverage trends
will be monitored this afternoon. A watch is possible should trends warrant.
DISCUSSION...MLCIN has generally eroded in the middle/upper Ohio
Valley early this afternoon as cumulus clouds have become more
prevalent on visible satellite. A couple of deeper
updrafts/thunderstorms have recently developed between Louisville
and Cincinnati. As the surface continues to heat this afternoon, the expectation is for additional storms to develop and intensify along
a stationary boundary. This activity will be aided be upstream,
subtle shortwave trough in Illinois/Indiana. Effective shear of
around 35 kts will promote marginal supercell structures. Damaging
wind gusts are the primary hazard with these storms. A conditional
tornado threat will exist right along the boundary, though low-level
shear rapidly decreases into the warm sector. Mid-level lapse rates
from this morning's soundings were poor, but isolated large hail
would be possible with supercells. The primary question is how large
the spatial extent of the severe threat will become. Such subtle
forcing for ascent may mean a generally cellular mode with more
isolated wind damage potential. Some CAM solutions do suggest
clustering is possible which would increase the wind damage threat
at least locally.