If the rain has not begun in your area, here are recommended preparatory measures:
Making sure critical prescriptions are filled.
Make sure your fuel tank is full.
Make sure you have extra cash (ATMs and credit card machines don't work when the power is out)
If you have a generator, make sure you have fuel. If you think you need a generator, now is a good time even if this storm does not pan out but get on that right away.
Consider a "inverter" to keep phone charged, computer charged, and, with a large inverter, maybe an appliance or two.
Backup critical data.