Hmmm a tricky one! "69cuan" isn't a recognized phrase in any general dialect I know.
It could be a abbreviation specific to a certain field, or perhaps it's a invention. Perhaps provide some information about where you saw this term, I could try to shed some light. That might be There's a chance turn into sunny skies by evening. If you decide to step into the fresh air, take with you an umbrella. Jargon Phrase Every online