Hurricanes Begin in Western Africa

A new study published by Tel Aviv University’s Prof. Colin Price and his graduate student Naama Reicher finds that “85 percent of the most intense hurricanes affecting the US and Canada start off as disturbances in the atmosphere over Western Africa…the larger the area covered by the disturbances, the higher the chance they would develop into hurricanes only one to two weeks later,” says Prof. Price.

The coverage of clouds acts as an indication of atmospheric disturbances. The more clouds in an area, the larger the disturbance. Using infrared cloud-top temperature data gathered from satellites, Prof. Price assessed the temperatures of the cloud tops, which grow colder the higher they rise. He then compared his cloud data with hurricane statistics—intensity, date of generation, location, and maximum winds—from the same period. “The disturbances that developed into tropical storms had a significantly larger area covered by cold cloud tops,” said Prof. Price.

According to Price, only 10% of the 60 disturbances originating in Africa every year turn into hurricanes. “We wanted to know what was so special about these disturbances. Was there something different about these storms at their genesis?” said Prof. Price. “We found that the larger the cloud coverage originally in West Africa, the higher the value of the accumulated cyclone energy in a future hurricane. The conclusion, then, is that the spatial coverage of thunderstorms in West Africa can foretell the intensity of a hurricane a week later.

“If we can predict a hurricane one or two weeks in advance—the entire lifespan of a hurricane—imagine how much better prepared cities and towns can be to meet these phenomena head on.”