A quick start to the Atlantic hurricane season saw five storms form so far this year, well ahead of normal pace of a normal year, before settling into a lull that’s lasted several weeks. The conditions that created this quiet period — an annual eruption of waves of dry air and dust from the Sahara rolling out across the Atlantic from Africa to the Americas — are ending just as the traditionally hurricane-heavy month of August begins.
The large cloud of Saharan Desert dust spent much of July meandering across the Atlantic basin, showing up on NASA satellites as a light-beige smudge spreading out from West Africa and reaching all the way to South America. While the dust itself doesn’t stops hurricanes, the dry air that carries it stops thunderstorms drifting across the Atlantic from growing into tropical storms.
“Once we move into the first week of August, we will see the dust diminish,” said Jim Rouiller, lead meteorologist at the Energy Weather Group. “This is basically normal, and it’s one reason why we see the big uptick in storms later in August.”
While hurricane season officially starts June 1, the most frenetic period is between August 20 and October 1, with the statistical peak coming on September 10. It’s during this time that the worst storms tend to form between the Caribbean islands and Cabo Verde off the African coast. The storms that form in this area, called the main development region, tend to last longer and carry more destructive power than any other systems.