Hi all...
Ive had a cursory look at other stations with either the TSMM or even VCTSMM and they are all from AUTO stations - meaning there is no human input into their creation. Mind you, that does not mean that it cannot be created by the coder.
Mammatus Cloud is coded as CBMAM so thats not it, and TSNO stands for Thunderstorms with no information....
I had a thought that it could indicate some sort of macro or microburst in the area, but Im not sure if an Auto station would have the ability to track that sort of data.
Anyone want to halt our speculation????