Christine,

Some good questions (whether the mods leave these posts here or move them is as variable as a tropical system....)

As far as the dust, it does seem that this year was more than in the past, but I also think that the technology has improved to the point that we can track it better than before. For sure it had a negative influence on tropical system formation.

There are other posts on this forum and elsewhere that describe the effects of El Nino, specifically increased and persistent shear which inhibited development of many systems.

Bill