I’m just a learner also, but I think that would likely be “E mao ana ka ua.” Mao is a stative verb according to
So its basic meaning is as a (completed) condition. My understanding is stative verbs have the idea of state being completed by themselves, so to indicate it is ongoing we would need to add the aspect marker e...ana. See section 5.2 of
I hope some fluent speaker will chime in.
‘Ae/Yes. The rain clears is okay for that too. The translation in English is in present perfect tense, meaning completed action. So if anything it would be Ua mao ka ua to be specific. If by chance one would want to say The rain was clearing, then that would be different. I think that can be said as E mao ana ka ua. I also defer to a fluent speaker for the best way to say The rain is clearing. I think Mao ka ua would work there too. The dictionary says mao is stative, meaning cleared but also it indicates that mao can mean to clear. So I am not sure if Ke mao nei ka ua would work. I see two instances of Ke mao nei in the old newspapers, one referring to sickness and another that seems to be an expression of some sort.
ulukau.org has the newspaper database as well as books online. It is a nice compendium of info. This is the link to the word search for the newspapers. http://nupepa.org/gsdl2.5/cgi-bin/nupepa?e=p-0nupepa--00-0-0--010---4-----text---0-1l--1haw-Zz-1---20-about---0003-1-0000utfZz-8-00&a=q