Etymology of abbreviation “PO” for dust devils?

[PeterNSteinmetz]

So I am studying for my CFII and came across the METAR abbreviation for dust devil, namely “PO”. I gather the French for dust is “poussière”, so I suspect a French derivation like BR.

@Winthrop - what do you think?

 

[PeterNSteinmetz]

So I found this site where the author did a bunch of research on these.

Apparently PO may just be the first two letters of poussiere.

Mysteries of the METAR, BC BR PO MI FU GR GS, Darren Smith, Flight Instructor

Darren Smith

www.cfidarren.com