I'm not sure the drought will have the same impact on finished tobacco products as it will on, say, corn - where we'll see significant price increases.
I'm not a tobacco expert, but my understanding is much of the tobacco used by blenders is grown overseas. Of longer term concern, however, is that American tobacco farms are already under significant pressure - political, regulatory, as well as standard agricultural challenges. A bad crop could send some over the cliff, resulting in fewer farmers and less overall tobacco on the market. That could increase prices over the long term (as opposed to a drought induced singularity that sends prices soaring). What we will likely see if that happens is that domestic production is replaced by foreign production. Impact to prices may be minimal, but impact to American rural culture will be significant. But that's the trend these past several decades.
At the end of the day, I fear American tobacco farms have more to fear from DC than they do the weather. Sad.