There is a very good chance this won't be happening. Might be a bit late now but if you can fly earlier, it would be better (although you'll be stuck in a typhoon with nothing to do for most of that day).

The impact of the typhoon is likely to start at around Monday evening (local time). The current aerodrome forecast has gale force winds hitting HKG from the north or northwest (which translates to cross wind at HKG) from around 6pm.

Also, given current forecasts, it's difficult to predict where the typhoon will land exactly, a bit of a 50-50 guess whether it will land to the east or to the west of HKG.

A direct hit or west landing will have a much greater impact on Hong Kong overall. Plus, the airport is located in the west. Expect force 12 winds in this case. A typhoon that lands in the east does not have as much of an impact as the terrain partially protects the city from the wind. Probably not much more than force 8 winds if this is the case. A few years back, a super typhoon landed nearby in the east of HKG, and some flights could still operate.