Simple answer? It didn't go anywhere. You are looking at a 00Z forecast (evening when surface temperatures are warmer) versus the 12Z forecast which is the early morning where surface temperatures are at their coolest.
The better answer to this is to truly understand what CAPE really is.
http://ww2010.atmos.uiuc.edu/(Gl)/guides/m...arams/cape.rxml
To me, your question sounds like you consider CAPE to be a physical object like a balloon (representing a large volume/parcel of air) or something like the boundary of a differential airmass such as a warm front that can be shifted as a whole by prevailing winds. I think you're close though because you can shift the atmospheric conditions that affect CAPE values.....not CAPE itself.
CAPE is all dependent on a specific location where you would take a parcel of air (think of the hot air ballon analogy) and lift it vertically through the atmosphere above that same location. That very parcel's physical characteristics such as dewpoint and temperature are very very important.
As you lift that parcel, it automatically cools due to decreasing air pressure. It will cool at a specific rate until it gets cool enough to become saturated...a cloud or fog in simpler terms. At this point, the air parcel continues rising, but at cools MUCH slower now that it is saturated. So, at what level in the atmosphere it becomes saturated depends on how much moisture it starts off with.
Since CAPE values are derived by calculating how much warmer the parcel is in relation to it's surrounding air temperature at a given level, the warmer it starts off from the lower levels will affect the CAPE values. So, that's why you will see CAPE values highest during the peak heating hours of the day and fall off at night.
What you are seeing on the models are likely where the surface airmass is more saturated (higher dewpoints) and warmer than elsewhere. Also, keep in mind what I mentioned above about the air temperature surrounding the air parcel. If colder air moves in aloft and the surface airmass has the same dewpoint and air temperature, then the CAPE will also increase.
Going back to the hot air balloon analogy seems the best way to learn about atmospheric thermodynamics. I know it helped me alot when I was first learning. What does a balloon pilot do to increase his altitude? He hits the burners and increases the air temperature inside the balloon relative to the outside air. Then, up he goes!
Also, the greater the difference in air temperature inside and outside of the balloon, the faster the rate of ascent.
All of this is why I just love cooling mid level temperatures and increasing dewpoints at the surface.
I hope this helps at least a little bit. I'm not a meteorologist (as my sig line indicates), so others that are can offer more where needed.
