Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas? Perhaps. But did you know the rainfall in a section of an African desert can effect the chance of a hurricane?
The Sahara Desert in Africa is the major source for African dust (or Mineral Dust) floating across the Atlantic to the Caribbean and South America each summer. I’ve been in Puerto Rico during one of those summer “dust clouds”. The sky is hazy but more reddish than grey.
However, it’s the north-western end of the sub-saharan Sahel Belt in Africa that can be a factor in Atlantic Ocean temperatures. The Sahel’s rainfall is a variable compared to the Sahara so if there’s more rain, there is less dust blowing from the African coast.
How does this effect the formation of hurricanes? Dr. Jeff Masters reports that when there is more dust, the water temperatures can fall by a full degree Celsius. Hurricanes need warm water to form, so more dust means cooler water temps.
Therefore the amount of rain in NW Sahel effects the amount of dust that blows over the Atlantic which effects the water temperatures which effects hurricane formation.
Got all that?
So what does it look like this year? There has been more rain in NW Sahel so there’s less dust so the water temps should be warmer so the likelihood of hurricane formation increases. But here’s the good news: the dust level won’t be as low as it was in 2005. You remember the 2005 Hurricane season, don’t you? Do the names Wilma, Rita, and Katrina ring a bell?
Also see Dust from Subsaharan May Affect Frequency of Hurricanes. Originally tipped off from the FriendFeed Hurricane Room.