This is the general direct that KC gets its rains. We normally don't get them when TMD gives a high percentage chance of coverage like 60% but when its is around 30 % we put the ark on standby. Today it's at 40%.
If you check this out you will see it is a static rain depression that is just growing. I have never seen seen anything quite like it.
It appears, if I had to guess be a trapped amount of moisture that is in a doldrum of upper air currents.