Just another update, the models are picking up on some explosive deepening that Nicole (aka the Perfect Storms) will do as it does all of it's trasitioning. Let me explain, the feature wants to become warm-core because of frictional and compressional heating, the feature then cannot sustain itself and the upper cold core system destroys the low level warm core feature and makes the transition to extra-tropical. Then the cold-core system builds around the warm-core center because the energy has no where to go and the storm can "bomb." An example would be Hurricane Grace, I'm currently doing some research on it, I'll post some of the links.

Here's a good page:
http://www.intellicast.com/DrDewpoint/Library/1122/

Here's another good page:
http://www.noaanews.noaa.gov/stories/s451.htm