[gembud] Off-Hour METAR Observations using SFLIST

Does anyone know how to get off hour METAR observations?  

For example,  this morning at KCMH, there was an ob at 1239Z, but I am only 
able to retrieve hourly obs...  (from UCAR): 


KCMH 151251Z 33009KT 8SM BKN013 OVC020 19/17 A2987 RMK AO2 SLP110 T01940167
KCMH 151239Z 33010KT 8SM BKN013 OVC020 19/17 A2987 RMK AO2

From our machine: 

 GEMPAK-SFLIST>l
 SFFILE   = METAR
 AREA     = @cmh
 DATTIM   = 12-13
 SFPARM   = text
 OUTPUT   = T
 IDNTYP   = stid
 GEMPAK-SFLIST>r
KCMH 151151Z 32011KT 8SM SCT018 BKN025 OVC140 19/17 A2987 RMK AO2 SLP110 BINOVC 
60000 T01940167 10200 20194 53013   
  
KCMH 151251Z 33009KT 8SM BKN013 OVC020 19/17 A2987 RMK AO2 SLP110 T01940167 
  
 Parameters requested: SFFILE,AREA,DATTIM,SFPARM,OUTPUT,IDNTYP.
 GEMPAK-SFLIST>


Do I need to use a different decoder to get these observations?  (Interestingly 
some stations allow me to get the off-hour obs, e.g. UNV) 

 GEMPAK-SFLIST>area = @unv
 GEMPAK-SFLIST>r
KUNV 151155Z AUTO 00000KT 7SM SCT010 OVC110 17/17 A2977 RMK AO2 P0004   
  
KUNV 151215Z AUTO 28003KT 10SM SCT006 OVC110 17/17 A2977 RMK AO2 LTG DSNT S 
  
KUNV 151235Z AUTO 00000KT 10SM SCT004 SCT017 OVC110 17/17 A2978 RMK AO2 
  
KUNV 151255Z AUTO 00000KT 10SM -RA SCT019 SCT060 BKN120 17/17 A2978 RMK AO2 
  
 Parameters requested: SFFILE,AREA,DATTIM,SFPARM,OUTPUT,IDNTYP.

Any insight is appreciated.  Thanks! 

- Phil