So sorry to change the date so last minute, but maybe it's best to err on the side of caution. Odds are Saturday will be clear. In case it isn't, though, I think it's better to reschedule it now instead of the day of the event.
FREE Karaoke at this restaurant from 9:30 pm onwards. It's located at the Outrigger Reef hotel in Waikiki. They don't have their regular menu at that time but after 10:00 pm they have a light menu of sliders, hot dogs, fries and such.