When does it stop being partly cloudy and start being partly sunny?

When the sky has more clouds than sun. It's the other way around with partly cloudy

It depends on your point of view pessimistic-partly cloudy optimistic-partly sunny

i wish it'd hit you again.

( [: forgive me. i think it's partly sunny all along, but that sounds a little saddening, no? "it's only partly sunny today..." or "today will be partly sunny..." personally, i'd rather it be only partly cloudy than only partly sunny. )

when the glass is 1/2 full

I was listening to the radio and the guy was like "tonight its going to be party sunny...."

and then stopped and he's like.

"well uhh, heh, party cloudy for that matter..."

I've heard both...I think it's what ever your local weather person uses as a term

meteorologists see the glass as half empty

perhaps at the silver lining.

When it's windy.