Well, indeed a Swiming pool in Sanur is not close to the met station in the airport :
if you look at the METARs published by the AvHerald ( same link as mentioned a few post earlier) they tell a different story ;
accident occurred at 07:10 according to them
WADD 130730Z 15006KT 110V270 9999 FEW017CB SCT017 30/25 Q1007 NOSIG
So CBs were reported .
Interestingly the preceding METAR was :
WADD 130700Z 09006KT 9999 BKN017 30/26 Q1007 NOSIG
which tell you all about the validity of a NOSIG in tropical areas....