Auë or auwë are the same. Both mean- oh, oh dear!, oh boy!, alas!, too bad!, goodness! Etc. Acc.: to Hawaiian Dictionary
My favourite sentence I have translated
I thought the spelling is auwē?
I thought auwe was a negative ( like punawahine suggests below) - "oh" to me can just be acknowledgement of something - could even be positive like "oh yeah! I get it!" So does aue (or auwe) mean both???
I have never used it for a simple 'oh'- it has much more emotion than that, in my experience.