When a known whopper of a storm is coming in, and folks still insist on a permit to enter the mayhem, they should ... leave an open visa draft that allows the NPS/FS/SAR to fill in the $$$ blank if/when an extraction is required.
This may well be the best idea of the bunch. "Something might happen" doesn't register with a lot of people, but when you put it in dollar terms, it's like another portion of the brain clicks on. "Whoa! Wait just a minute here. You mean this might
cost me something?"
Laugh if you like, but, yes, people will respond more to dollars than to a general "something really bad might happen" warning.
HJ