Inform visitor of site slowness then re-direct to page

My server is having a few problems rendering my content, and I am in the middle of finding a suitable expert to help. In the mean time, I would like a basic page shown to my site visitors immediately on their arrival informing of this, and to be patient whilst the page they intended to view renders. It then to forward to their page.

How best to implement this to avoid loss of page rank etc.

I’m mindful that it might take a while for me to source a good server admin and for any fix to be implemented, so this might be needed for a few weeks.

Thank you for any help with this.