I'd think the activity north of OAX could become surface-based as it pushes further east into lower CINH (for a surface-based parcel). RUC mesoanalysis shows 0-6km shear has increased +10kts in the past hour in some spots in response to the approaching shortwave perturbation aloft at 500mb (evident in moisture channel imagery) which is increasing the midlevel kinematic profiles. I wouldn't be surprised to see the MDT risk verify based on hail reports given the extreme > 4000j/kg MLCAPE and low wet-bulb zero levels across much of the area. WRF showed a large-scale convective line stretching from the Dakotas southward into the MDT risk zone on last night's run -- which is likely given the degree of capping and deep shear. Nonetheless, I wouldn't be surprised to see some significant wind/hail reports, especially with any embedded supercells or bow echo structures in the line (or ahead of the line). I'm glad to see the >70 tds have held despite the strong insolation / sfc diabatic heating (which has weakened CINH while incresing CAPE and still maintaining relatively-low LCLs). I'm thinking that large hail and damaging winds would be the biggest threats given the weak low-level shear.