It is spelled Huwai.
http://www.fallingrain.com/world/ID/28/Huwai.html
http://www.worldweatheronline.com/Huwai-weather/Nusa-Tenggara-Barat/ID.aspx
http://www.maplandia.com/indonesia/maluku/maluku-tenggara/huwai/
Ok, we have 2 different spellings but you did confirm the spelling that you have