Latest RUC indicates STRONG southerly 50-60 KT LLJ will develop over the Missouri valley later this evening and overnight, strong warm advection/isentropic lift associated with it will keep convection going, as it organizes into a rather potent forward propagating MCS even w/ loss of diurnal heating. Were already STARTING to see some signs of that happening as we speak WRT convective orientation.
Airmass is still VERY unstable with lowest 100mb mean layer CAPE in excess of 2500 J/kg reaching as far N as SERN SD/ extreme SW IA and good boundary layer moisture with SFC dewpoints > 64F.
Convection further south in more strongly capped environment over SRN KS, OK and TX may translate into a second however, possibly SOMEWHAT weaker MCS.