Information is kept updated at https://trafficinfo.westjr.co.jp/sanyo.html
note this page only covers West JR section of the Shinkansen (Hakata - Shin-Osaka).
It looks like the typhoon won't affect the trains till evening hours, so you should leave early and be prepared for a packed train (everyone else is trying to get out of Kyushu before late!) if you have a non-reserved ticket.
@salixlucida thank you so much for your help! I’ll see about taking a train earlier to maybe be ahead of the rush. I haven’t reserved yet so I think it’s best I get to the station as soon as possible.
More queer, more garden.