UK Mean Wind data - Columns in the WM table

Table Description - Columns in the WM table - How to start filtering the rows of data out

The surface observation data are in a simple ASCII format.

Table Description:

This entity contains values of mean wind and gust direction and speed measured during one or more hours ending at the stated date and time. "Hour ending" is contrary to the CDB practice, which uses hour beginning at the stated time, but provides a uniform practice in MIDAS, and simplifies the creation of SQL views. The rows in this table are of two types: This table is NOT intended for: Identifier is DCNN + anemograph site number.

Columns in the WM table:

For the convenience of users, the WM file column headers are available for download in Excel or as a comma separated text file

PK Attribute Description / Units
* ob_end_time Data and time at end of observation
* id_type Identifier type
* id  
* ob_hour_count Observation hour count
  met_domain_name Message Type
* version_num Observation version number - Use the row with '1', as this has been quality checked by the Met Office
  src_id Unique source identifier or station site number
  rec_st_ind State indicator for the record**
  mean_wind_dir Mean wind direction - The wind direction from which the wind blows, is measured in Degrees (true). The entry for an east wind is 090, that for a south wind 180 and so on clockwise. Note that zero values in both wind speed and wind direction fields indicate that there was no wind blowing at the time of observation. More...
degs true
  mean_wind_speed Mean wind speed
knots. Wind mast elevations from selected stations are available here (MIDAS users only).
  max_gust_dir Direction of maximum gust
degs true
  max_gust_speed Speed of maximum gust
  max_gust_ctime Clock-time of maximum gust
  mean_wind_dir_q QC code - mean wind direction**
  mean_wind_speed_q QC code - mean wind speed**
  max_gust_dir_q QC code - maximum gust direction**
  max_gust_speed_q QC code - maximum gust speed**
  max_gust_ctime_q QC code - maximum gust time**
  meto_stmp_time Met Office receipt stamp time
  midas_stmp_etime Elapsed time to storage in MIDAS
  mean_wind_dir_j Descriptor - mean wind direction**
  mean_wind_speed_j Descriptor - mean wind speed**
  max_gust_dir_j Descriptor - max gust direction**
  max_gust_speed_j Descriptor - max gust speed**

** Details available to registered users only.

More information about the Met Office surface data is available in the documentation provided by the Met Office.

How to start filtering the rows of data out:

  1. As the data arrive at the Met Office it undergoes quality control to check that the data are correct and consistent with the surrounding data points. Whether the process has occured or not is indicated by the version number (1 is the one to use as indicated in the table above).

  2. To show the progress of the data through the quality control the various variables will have an associated _q value (e.g. mean_wind_dir_q). This _q value will have different values for each record (see details in table above).

  3. While the Met Office MIDAS system overwrites the existing entry in their database the BADC's MIDAS entries do not as the BADC takes snapshots of the the MIDAS database from time to time leading to duplicate entries occuring in our archive. If duplicate records are found, check the associated meto_stmp_time to determine which record is the most recent one - this is the one to use and the other(s) can be ignored.