[aprssig] Symbols

[Robbie, wa9inf]

What is the actual purpose of the Sky Warn, (Tornado), symbol? My 
thoughts would be to used it to spot a Tornado.

Is it to be used by a Trained Certified or other observer to note his 
House/Station, is it to be used to report a Tornado by said spotter, or 
just to be used to let the network know the station is owned by a 
certified Sky Warn spotter?

Seems to serve no purpose when used instead of a house/station symbol!

Robbie