QCMS Subjective Intervention Capability

Two text files, a "reject" and an "accept" list provide the capability to subjectively override the results of the automated QC checks provided by the Quality Control and Monitoring System. The reject list is a list of stations and associated input observations that will be labeled as bad, regardless of the outcome of the QC checks; the accept list is the corresponding list of stations that will be labeled as good, regardless of the outcome of the QC checks. Applications reading the lists (e.g. the MSAS analysis) will then reject or accept the stations specified. In both cases, observations associated with the stations in the lists can be individually flagged.

The following reject list, for example, indicates that all pressure obs associated with mesonets UTMESNET and SCHLNET will be withheld, as well as SLP, altimeter, and temperature observations from the METAR station KP69. KP69 observations of pressure change, temperature, dewpoint temperature and winds will be quality controlled normally. Also, station C0004 from any provider will have it's dewpoint observations rejected, but all other observations will be normally quality controlled. A new capability as of OB4 is that by specifying "ALL-MESO" as the provider, and leaving the station ID blank, you can reject all observations of the specified type (station pressure is used here) for all mesonets.

          Quality Control Monitoring System QC Reject List:  "1" => Flag observation as bad 

StaID     |Provider  |SLP   |Alt   |Mpchng|Theta |Td    |Wind  |MSLP  |MDPD |RR    |Pchng |P     |VV    |RH    |T
KP69      |METAR     |1     |1     |0     |1     |0     |0     |0     |0    |0     |0     |0     |0     |0     |0
C0004     |          |0     |0     |0     |0     |1     |0     |0     |0    |0     |0     |0     |0     |0     |0
          |UTMESNET  |1     |1     |0     |0     |0     |0     |0     |0    |0     |0     |0     |0     |0     |0
          |SCHLNET   |1     |1     |0     |0     |0     |0     |0     |0    |0     |0     |0     |0     |0     |0
          |ALL-MESO  |0     |0     |0     |0     |0     |0     |0     |0    |0     |0     |1     |0     |0     |0

Example Entries *************************************************************************************************
KGCC      |METAR     |1     |1     |0     |0     |1     |0     |0     |0    |0     |0     |0     |0     |0     |0
WPG       |METAR     |0     |1     |0     |0     |0     |0     |0     |0    |1     |0     |0     |0     |0     |0
4010      |UDFCD     |0     |0     |0     |0     |0     |1     |0     |0    |0     |0     |0     |0     |0     |0

Spatial Consistency Check/MSAS Analysis Variables:

Label      Variable                                Observations Used
-----      --------                                -----------------

SLP        NWS sea level pressure                  SLP
Alt        Altimeter setting                       Alt + Alt* [P, Elev] + Alt* [SLP, where Elev <= 25 m]
Mpchng     MSAS pressure change                    Mpchng* [Alt]
Theta      MSAS potential temperature              Theta* [T, Alt, Elev]
Td         Dewpoint temperature                    Td + Td* [RH, T]
Wind       Wind speed and direction                Wind
MSLP       MSAS pressure reduction                 MSLP* [Alt]
MDPD       MSAS dewpoint depression                MDPD* [T, Td or RH]

Other Observations:

Pchng      3 hour pressure change
P          Station pressure
VV         Visibility
RR         Precipitation (rate and/or accumulated amount of any duration)
RH         Relative humidity
T          Air temperature

Note - "*"'s indicate variables that are derived from other observations, which are listed enclosed
in the brackets.  For example, the altimeter variable processed by the spatial consistency check
and analyzed by MSAS includes reported altimeter observations, plus altimeter values calculated
from station pressure and elevation, plus sea level pressure obs if the station elevation is <= 25 m.
If any of the observations needed for the derived obs are on the reject list, the variable will
not be calculated.  The results of the spatial consistency check will be stored in the QC database
associated with the primary variable used in the derivation, e.g., relative humidity QC results
will include the spatial consistency check results from the dewpoint obs derived from the
relative humidity obs.

On AWIPS, the subjective intervention lists reside in the following directory: /data/fxa/LDAD/fslparms. The lists may be edited by hand (with any text editor), or through the LDAD Monitoring and Control System.*

When changing the reject list MSAS persistence grids need to be eliminated to give the system a clean start. To do so, "restart" through the LDAD Monitoring and Control System*, or log onto PX1 and PX2 and type:

Example entries are provided in each reject and accept list. Notice that for each station, both station and provider names may be specified. Provider names currently being processed are listed in /data/fxa/LDAD /fslparms/sfchqcin.dat. National datasets have one of the following provider names: "METAR" (includes "ASOS" and "OTHER-MTR") or "MARITIME". LDAD mesonets retain the same provider names specified at the top of the LDAD /data/fxa/LDAD/data/*.desc files. Blank provider names are allowed, but may result in multiple stations with the specified station name being rejected or accepted. This occurs when different data providers use the same station name.

The QCMS also provides the capability to accept or reject observations from all stations with a specified provider name. To utilize this option, fill in the provider and observation columns, but leave the StaID column blank. Note, however, that these entries must be listed at the bottom of the intervention lists.

To view the subjective intervention lists currently in use, click here.

Last updated 7 November 2005.

* Note that as of this date the LDAD Monitoring and Control System is not working properly. You should edit the lists with a text editor and do the restart using WFOA_MSAS_Restart as described above.

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