With the strong blowups, like you mention with either Andrew or Charley (another case is Opal in 1995), usually the cause is determined, though maybe not for several years. It may also be a multitude of causes, all interrelated, leading to deep intensification. With Andrew and Charley, both small storms, they reacted very violently to favorable external forcing, spinning up in a rapid period of time. The exact causes, however, still remains up for debate with Charley. Andrew is a bit more straightforward, with very favorable atmospheric conditions (internal factors not withstanding), but more effort has been focused on determining its actual intensity -- cat 4 or 5 -- versus on researching the storm itself.