Weather Whys; Sahel and Hurricanes

This is weather-wise. For most of the last two decades, residents of the Eastern Seaboard have largely been spared the wrath of major hurricanes. The period from 1970 through 1987 saw relatively few strong hurricanes in the Atlantic in Caribbean. Then, within the next two years, super-hurricanes Hugo, Gilbert, and Joan threatened and sometimes devastated communities in their paths. Dr. William Gray of Colorado State University has found a link between rainfall patterns in the Sahel region of Africa and strong hurricanes in the Caribbean in Atlantic. The Sahel is a semi-arid transition region south of the Sahara Desert and north of the equatorial grasslands. From 1970 to 1987, when few strong hurricanes threatened the east coast of the United States, the Sahel region experienced severe drought, but during the previous 22 years, strong Atlantic and Caribbean hurricanes were abundant and so was rainfall in the Sahel.

Dr. Gray concludes low-pressure systems may develop more easily over the Sahel than that region is wet. Those systems then travel westward over the Atlantic with the prevailing winds and can develop into tropical storms or hurricanes over a warm summer ocean. Previous studies have it shown a link between Sahel rainfall and Atlantic or Caribbean hurricanes, but Dr. Gray and others say the new evidence really isn't surprising. Since 1988, the Sahel seems to be entering another wet phase, and if the theory holds, that is, if the past correlation was not just random coincidence, that could mean an increase in strong Atlantic and Caribbean hurricanes over the next 10 or 20 years. Otherwise is made possible with the assistance of the Cooperative Institute for Mesoscale Meteorological Studies, the Oklahoma Climateological Survey, and the School of Meteorology, all at the University of Oklahoma. I'm Drew Barlow.