Noah's story is written as an actual event. An event can be literal and a metaphor at the same time.
You do understand that there was no global flood, right?
“It’s a metaphor” it’s a common tactic used when religionists are held to a consistent, identifiable standard. Christians will claim that the genesis fable is a standard by which we can identify the beginning of a 6,000 year old earth. Is that accurate or not? If not, what standard (other than none or personal preference), is used to reach that conclusion? Similarly, if the Noah fable is not literally true, what does that suggest about the veracity of other biblical tales? In other words, is the message of the bibles a cold, unalterable law:
Ye must believeth this, or be damned, or rather an exercise in pick and choose theism?
Are we to accept that the bibles range from fact to fiction, from literalism to metaphor helter-skelter, and humans are then asked to pick and choose which aspects are literal and which are not?
Is the biblical flood literal Ior not? Is Joshua's sun-standing still (i.e., Earth stopping its rotation) a true rendering of an historical event, or not? Is Adam and Eve and original sin true (this one is primary, for without it, all the rest is unnecessary).
Kinda. Sorta. Yes and no, some yes, some no. Super. Make it up as you go. That's what you embrace. Meanwhile, the underlying message remains:
Believe this, or be eternally, forever, always and from now until never – roasted in Hell.
Sorry, but humanity can do better.