Table 7.   Code table for observation quality markers (last revised 2/14/2018 - should be up to date).
 
Quality Marker Definition
       0 All steps: Keep (always assimilate).  Applies to pressure, height, wind, temperature, specific humidity, rainfall rate, precipitable water and cloud top pressure.
       1 All steps: Good.  Applies to pressure, height, wind, temperature, specific humidity, rainfall rate, precipitable water and cloud top pressure.
       2 All steps: Neutral or not checked (default).  Applies to pressure, height, wind, temperature, specific humidity, rainfall rate, precipitable water and cloud top pressure.
       3 All steps: Suspect.  Applies to pressure, height, wind, temperature, specific humidity, rainfall rate, precipitable water and cloud top pressure.
     4-15 All steps: Rejected (don't assimilate), as defined below (see % below table):
                 4 Step OIQC:  An observation with pre-existing quality marker 0 (keep) is flagged.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.
                 5 Step OIQC:  An observation with pre-existing quality marker 1 (good) is flagged.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.
                 6 Step OIQC:  An observation with pre-existing quality marker 2 (neutral/default) is flagged.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.
                 7 Step OIQC:  An observation with pre-existing quality marker 3 (suspect) is flagged.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.
                 8 Step PREVENT: An observed pressure on any level is > 100 mb below model (guess) surface pressure.  Applies to pressure, height, wind, temperature and specific humidity.

Step PREVENT: An observed pressure is < 0.  Applies to pressure, height, wind, temperature and specific humidity.

Step PREVENT: An observed surface pressure is above 450 mb or below 1100 mb.  Applies to pressure, height, wind, temperature and specific humidity.  (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: A non-pressure observation fails a limit check.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.   (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: An observed surface pressure is > 100 mb above or below model (guess) surface pressure.  Applies to pressure, height, wind, temperature and specific humidity.   (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: An overland TOVS clear, partly-cloudy or cloudy satellite temperature sounding report at or north of 60 degrees south latitude with pressure on level at or below 100 mb.  Applies to temperature and specific humidity.  (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: An overland TOVS partly-cloudy or cloudy satellite temperature sounding report south of 60 degrees south latitude with pressure on level below 100 mb.  Applies to temperature and specific humidity.  (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: An overland or oceanic clear, partly-cloudy or cloudy satellite (TOVS, GOES, DMSP) temperature sounding report. Applies to specific humidity on all levels.  (Note: Prior to 12/04/2007 this case received quality marker 9.)

Step PREVENT: A surface marine wind observation is reported as calm, but the model (guess) surface marine wind is greater than 5 m/s. Applies to wind.

Step VIRTMP: A virtual temperature is generated from a specific humidity observation where either the specific humidity has a rejected quality marker other than 9 or 15  - or -  the specific humidity has a rejected quality marker of 9 or 15 and the sensible temperature quality marker is rejected but with a value other than 9 or 15.  Applies to temperature.
                 9
(see % below table)		 Step PREVENT: An observation error is missing (does not apply for RUC network).  Applies to surface pressure, height, wind, temperature, specific humidity and precipitable water.  (Note: If  surface pressure observation error is missing, this quality marker is set on all other data on surface level - i.e., height, wind, temperature and specific humidity - regardless of whether or not its observation error is missing.)

Step PREVENT: A moisture observation is above 300 mb.  Applies to moisture.

Step VIRTMP: A virtual temperature is generated from a specific humidity observation where the specific humidity has a rejected quality marker of 9 or 15 and the sensible temperature quality marker is either not rejected or is rejected but with a value of 9 or 15.  Applies to temperature.  (Note: Prior to 12/04/2007 this case received quality marker 8.)
               10 Step SYNDATA: A non-synthetic bogus mass report is in the vicinity of a tropical storm.  Applies to pressure (only) on all levels of the mass report.

Step SYNDATA: A dropwinsonde wind report is in the vicinity of a tropical storm.  Applies to wind  (only) on all levels of the wind report.

Step PREPACQC (obsolete): An AIREP or PIREP aircraft report in Table A entry AIRCFT is used to generate a superob report.  Applies to wind and temperature.

Data producer: A wind profiler report in Table A entry PROFLR fails both median and shear checks performed by NOAA/ESRL/GSD.  Applies to wind.
               11 NCEP/SDM: An observation with pre-existing quality marker 3 (suspect) is flagged.  Applies to pressure, height, wind, temperature and specific humidity.  This is currently not used.

Data producer: A wind profiler report in Table A entry PROFLR does not pass median and shear checks performed by NOAA/ERSL/GSD (results are inconclusive).  Applies to wind.
               12 NCEP/SDM: A non-profiler observation is on the reject list.  Applies to pressure, height, wind, temperature and specific humidity.

Data producer: A wind profiler report in Table A entry PROFLR fails shear check performed by NOAA/ERSL/GSD, but passes median check.  Applies to wind.
               13 All automated quality control steps: A non-wind profiler observation failed one or more checks.  Applies to pressure, height, wind, temperature, specific humidity and precipitable water.

Step CQCPROF: A wind profiler report in Table A entry PROFLR failed one or more checks.  Applies to wind.

Data producer: A wind profiler report in Table A entry PROFLR fails median check performed by NOAA/ERSL/GSD, but passes shear check.  Applies to wind.
               14 NCEP/SDM: An observation is assigned a purge flag.  Applies to pressure, height, wind, temperature and specific humidity.
               15
(see % below table)		 Step PREPRO: An observation is flagged for non-use by the analysis.  Applies to pressure, height, wind, temperature, specific humidity, rainfall rate, precipitable water and cloud top pressure.

% - NAM and GFS/GDAS GSI analyses only: Observations normally used by the analysis when their quality marker is < 4 (based on their report type and variable) will be MONITORED  (but NOT USED) by the analysis when their quality marker is 9 or 15.   (Observations with quality marker 4-8, 10-14 will NOT be monitored nor used by the analysis.)  (Note: Non-GSI analyses currently do not use any observations with quality marker > 3, as they are not set up to monitor observations.)