Typhoons and Beach Closings?

Is there a place where one can look or another definitive way to know as to whether a beach will be “officially closed” for swimming/surfing when a typhoon nears? By “officially closed”, I mean when the cops come to tell you to get out of the water.

I’ve been at the beach (Wushi) before when all the shops were closed due to an incoming typhoon, but we could still go out there, and there were more than a few people surfing. I’ve also been to another beach (Jici) when there was a typhoon over Okinawa, where there were cops on the shore telling people not to go in.

For example, the swell reports are looking nice for the weekend (well, there is a big on-shore wind, but we’ll see) but we don’t know whether the beach will be open or not.