What is the idiom for "as anyone can see" or "clearly"?

I keep wanting to say "the handwriting on the wall," but that's not correct. The place I'm trying to use it is, "Alice likes Bob, Carol likes Bob, Alice thinks Bob likes her, but Bob dates Carol, and so as anyone can see, Bob did not like Alice."

What is the appropriate idiom here?

There are many (in addition to ermmanen's clear as day and plain as day [but both without the articles]), including

• clear as a bell
• as plain as the nose on your face
• beyond a shadow of a doubt

If you want a very colloquial term you could just end the sentence with duh, meaning

a statement perceived as obvious

clear as day (or plain as day)

to be obvious or easy to see

She's in love with him - it's as plain as day.

And some other contenders:

• as plain as the nose on your face
• as plain as a pikestaff
• blindingly obvious