in the following Jens Waterboer will describe a problem of generating a map of the "1000-500 hPa thickness" in DAW.
If the 1000 hPa-level is negative, the WMO sets a "5" in front of the coded level and a "6" if the level is more than 100 meters below the station-level.
So the value "509" means a level of "-9" gpdm.
In the calculation of the "1000-500 hPa thickness" the value "509" are subtracted from the full 500-hPa-level with some very curious maps (see the attached maps).
And here is the corrected map:
You can make the corrections with the "Quality Control Panel".
You mark the area with the wrong data and start the "Quality Control Panel".
You will find some stations with values like "549" in the field "Height".
You delete the value "5" and set a "minus" instead of it, Accept Entry and afterwards make a new run of the "Retop" and you will have the corrected maps.
Anyone else who has made these experiences?
With best regards,
Stefan Lichius + Jens Waterboer