Was just about to write on the same topic! Four active storms in the area!

Your old stomping ground, Pingtung, has had 1250mm in the last 5 days. That's massive rain.
Has to be one of the wettest places for total rainfall in the known universe - proving that yet again.

Today, your other old haunt, Dong He, is in the top 5 with 370mm so far today - which could well hit 500 by midnight.

This appears to be caused by a typhoon that has sprung up just to the south of Pintung/Kaohsiung. Haven't seen too many typhoons form so to close the south coast before - normally it's well to the east.

Then as you say, potentially another double-whammy to impact up north with a very unusual track for Saudel going partially down the Taiwan strait from a northern entrance!

It was being projected to curl around to affect the rarely hit northwest tip of Taiwan, but is now forecast to be north of that.

It almost looks like they're being guided into the same spot - possible weather manipulation warfare?