The national Hurricane center alternates from boy to girl is why , The next name on the alphabet list is Tony .
I don't know why exactly Sandy, but they go in alphabetic order of the Hurricane names.
They should have named it Lilith.
At the start if hurricane season they start with the letter 'A' for naming tropical depressions and go through the alphabet.
It was that or 'Trish'
because Judith was taken