Avail is the verb of available?

[Tedwonny]

I received an email from one of my colleagues:
...I am sure you stand another chance when opportunities do avail.

I've checked several dictionaries such as Cambridge online and Oxford online dictionaries but seem not to be able to find the right shade of meaning for the rather limited use of the word 'avail'. I gather from the context that 'avail' seems to be the verb form of a frequently used adjective 'available'. Has this become a prevalent use? Is it correct English in any case?

THANKS

 

[Raymott]

It's not uncommon, but it's rather formal. "when opportunities avail" = "when opportunities avail themselves" = "when opportunities become available".

 

[Tdol]

I hear it quite a lot here in the Philippines, usually without a reflexive pronoun, which sounds odd in most contexts to my BrE ears.