Essentially what this is showing is that there's a legitimate threat of tornadoes during the overnight across NC as a pair of mesolows streak across the state in concert with a 125 knot upper level jet streak over western NC and southwestern VA and southern Virginia. You can see in the sounding profile in the upper left hand corner how the wind barbs (in white) on the right hand side of the picture change quite rapidly just near the bottom of that image from southeasterly to southwesterly several thousand feet up, that's indicative of a robust low level shear, a necessary ingredient in tornado formation. What I'm also pointing out here is the storm relative helicity (or SRH) which essentially measures the potential of updraft rotation in a thunderstorm is pretty high in this case. Although subsequent runs showed appreciably less SRH in/around RDU, you usually only need 100-300 SRH or so to have a favorable environment for tornadoes, we may have double that. My biggest issue with this setup is the possibility of there being too much competing convection that could steal upward motion and convective available potential energy (CAPE) away from other surrounding thunderstorms. In order to have the most favorable environment for tornadoes you not only need a considerable amount of low level shear and instability, but the storms need to be discrete and isolated in nature, as opposed to being conglomerated into multicellular clusters, which may occur here. Even so, there's still a decent shot of a few isolated, brief, spin-ups as a multiple rounds of storms push through central and eastern NC beginning later this evening.
