Oh, I'm SO sorry you're in the path! Are you sure you're on high enough ground? If not, please evacuate!!!
You need supplies for yourself as well...bottled water, flashlights, food that doesn't require refrigeration (don't forget a manual can opener), a porta-potty, & plenty
of hand-sanitizer, etc. Be aware that those hand warmers for keeping your BP warm can run hot enough to burn him...you need to monitor the temperature (temp.
gun or thermometer) & wrap them in cloth or paper, so they don't touch him.
For best results in emergency situation: keep your snake in a secured pillowcase, then keep that in an "ice chest" (or thick styro-foam box like food & reptiles are
air-shipped in. It's much easier to keep him warm enough in that confined (& more importantly) insulated space, & your hand warmers will go much further that way.
If you have to evacuate, better he's packed this way & ready to go.
Please stay safe & let us know you're ok when you can (I'm sure you'll be without power for a while).
And I think you meant to say "hygrometer" (not hydrometer)? I think measuring the exact humidity is the least of your worries in this.