Adding splash page (pop up) prior to homepage

Omeka Classic
1

Hi,

Is it possible to add a splash page or a pop up image prior to the homepage? It could be similar to a gallery static image. Thank you.

Here is our WIP website:
http://sms-sandbox.parsons.edu/guatemaladespues/

2

Something similar to this WP plugin: https://wordpress.org/plugins/very-simple-splash-page/