Typhoon No. 12 and Air Pressure

I was measuring air pressure during Typhoon no. 12 this year and here is a graph of the air pressure change while the typhoon was passing Tokyo. It dropped from 993 hPa to 984 hPa. While not a huge drop, it's still notable for the rate of change.

Here the path. Tokyo is where the blue dot is. It's quite far away and we had not much wind.