I suppose that I would prononce "Fornal" like "terminal" for example. But it isn't well definited for Polish. We prononce "a" or "e" like Polish sounds and it isn't well precised how to prononce this sound in English, for me, this is something between so everybody prononce it quite different, it depends on his level of English or simply on his predisposition to language. There isn't any rules but it's only my impression, I don't know what the specialists say
If we prononce "Fornal" with Polish rules of prononcation, it will be "Fornal" with "a" like in French "page" for example)