"has cleared" would be best as Ua mao .... . The vog clears should be an accepted answer.
I'm tempted to agree, but that does threaten to create a sentence like "Ua mao ka ua."
‘Ae / Yes. That is exactly what you can do. That is a legitimate sentence.
Why is it vog and not fog?
Because it is referring not to a water based mist but a smoke based haze caused by volcanic emissions. vog = volcanic fog.
Such a cool word! I'm from San Francisco where we have just plain clean fog. :-)
When referencing a completed action, ua will preceed the verb...3. Common part. preceding verbs and denoting completed or recently completed action; to become. (Gram. 5.2.) (PPN kua.) Wehewehe.org
So does that suggest that if it were a choice, "ua mao ka polalauahi" would have been (even more) correct?
‘Ae / Yes
"polalauahi" really seems like a compound word...
Google Translate was able to yield "smoke screen" from "polala uahi". Is that relevant?