Oh the fun of processing METARs.  Behold the METAR site MROC 	Juan 
Santamaria, Costa Rica.  Here's the 0z ob
SACS31 MROC 090000
METAR
MROC 090000Z 25005KT 5000 BR FEW005 SCT015 23/23 A2993 NOSIG=
and here's the 1z ob:
SACS31 MROC 090100
METAR
MR0C 090100Z 24005KT 3000 BR FEW002 BKN010 23/22 A3000 NOSIG=
Notice what's wrong? :)  So the Oh became a zero!  So the KWBC collective 
then missed it.
SACA35 KWBC 090100
METAR
...snipped...
MROC NIL=
So should I account for this in my METAR ingesting code somehow or alas, 
the 1z ob on 9 August 2017 is lost forever for MROC :(
daryl
--
/**
 * daryl herzmann
 * Systems Analyst III -- Iowa Environmental Mesonet
 * https://mesonet.agron.iastate.edu
 */