While there is more agreement on this storm system in a general sense among the various models, there is still a pretty noticeable difference in timing. The spread between frontal passage at any location is running about 6 hours between the fastest model and the slowest. SPC has gone with a slight risk on Wednesday.
Each image below shows one mode's forecast for the position of the Low pressure center as of 7pm CDT Wednesday. The NAM (top image) places the low in north central Kansas with a fairly sharp dry line -- indicated by the changeover from oranges through greens to grey over 60-70 miles. That dry line and low would be fairly-well positioned to bring a line of storms from Salina southward. The GFS, which has been moving the system more quickly than the other models, would have the low pushed all the way into central Iowa. That would tend to have any storms much further east, maybe along a Kansas City to Tulsa line.