Isolated severe wind gusts will also be possible from parts of the mid Missouri Valley east-southeastward into the southern Appalachians. ...Central and Northern Plains... West-northwesterly mid-level flow will be in place on Wednesday from the northern Plains into the Great Lakes. Within the flow, a subtle shortwave trough is forecast to move into the central and northern High plains during the afternoon. At the surface, a cold front is forecast to move southward in the central Plains, with a lee trough located in the High Plains. Thunderstorms are expected to form near the trough and move eastward across the central and northern High Plains during the late afternoon and early evening.