Mark:
Stu added the two cloudbase tags you inquired about to the latest release of WeatherCat. The release is still in beta, but I have tested the tags and they work.
Here is the note that covers this feature in WeatherCat 2.1 Build 1201 Beta 1:
CLOUDBASE can now be used with the STAT$ tag to return the current cloud base - for example:
STAT$CLOUDBASE:CURRENT$ HEIGHTUNITS$
Note: Will only work with CURRENT.
So, STAT$CLOUDBASE:CURRENT$ returns the current cloudbase and HEIGHTUNITS$ returns the units (feet or metres).
I am wondering if you would be so kind as to include this nice improvement for WeatherCat users in your next version of the SteelSeries?