A couple of other suggestions:
Depending on the severity of the storm and the room between me and other objects, I usually start the engine and leave it in neutral. This saves me time should something unforeseen happen, and eliminates the chance that Murphy and his law will come into play.
Besides all the good comments above, I would consider tethering to the jack lines too.
Don't kid your self, squalls can be down right scary!!! In one last summer we hit 8.8 knots with a bare pole.