"Ydy hi'n bwrw eira?"
Translation:Is it snowing?
So, i noticed:
Bwrw eira = to snow.
Bwrw glaw = to rain
And looked up Geiriadur Pryfysgol to check it and got:
Bwrw gwallt = to shed hair.
Bwrw blew = to shed fur.
Seems as though ‘bwrw’ means ‘to hit’ (like in the hover notes) but also ‘to cast (away)’:
Bwrw golwg = to cast a glance.
Bwrw allan = to cast out / to pour out Etc etc.
No, "Tywydd" is a masculine noun e.g "Y tywydd" or "Tywydd gwlyb". SiblingCreature is pretty close to the mark, as constructions where a general "It" is referred to use "Hi". Compare "Mae hi'n saith o'r gloch" (It is seven o'clock), where hi is used despite "Amser" being a masculine noun.