Since its raining, are you allowed an umbrella to bring to the test center???
Take one that you can afford to lose if worst comes to worst. Leave it in the hall if you need to. Hopefully the proctor isn’t a rule nazi and lets people leave umbrellas at the front of the room.
(incidentally, this is what waterproof coats with hoods are for)
Of course, you’re not allowed to wear items with hoods into the LSAT either…
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