They're pretty much all cirrus-equivalents, granted, but they're still water (more precisely, water ice) clouds. That is, unless NASA is misinterpreting them, but seeing as they're, like, the end-all-be-all experts on Martian climate, I reckon that's unlikely.
Even barring that, however, dust clouds would also cause issues for celestial navigation.
They're pretty much all cirrus-equivalents, granted, but they're still water (more precisely, water ice) clouds. That is, unless NASA is misinterpreting them, but seeing as they're, like, the end-all-be-all experts on Martian climate, I reckon that's unlikely.
Even barring that, however, dust clouds would also cause issues for celestial navigation.