document: The 1990 Atlantic hurricane season had more storms than usual and some forecasters predict that 's just a hint of more frequent and more forceful hurricanes in the coming years . But this year 's batch did not include the devastating storms of years past and at least one forecaster thinks 1991 will be a calmer year . The season ends today . Dr. William Gray , a professor of atmospheric science at Colorado State University , thinks a dry spell in West Africa during the past two decades explained the reduction of storms along the eastern seaboard in the last 20 years . In 1988 and 1989 , there was near normal rainfall in the Sahel , the semi-arid land on the southern fringe of the Sahara Desert . Some meteorological experts think the rainfall signaled the end of a 20-year drought - and may have spawned Gilbert in 1988 and Hugo in 1989 . Gray on Thursday predicted a below-average hurricane season in 1991 . He based his forecast on several factors , including an anticipated below-average rainfall in the Sahel . But Gray and other forecasters agree that the general outlook for the 1990s and the early years of the next century is for more intense hurricanes than those of the last two decades . `` We 've been through a real long period of hurricane inactivity in the '70s and '80s up until 1985 , and I think we 're coming out of that , '' said Bob Sheets , director of the National Hurricane Center in Coral Gables . `` Perhaps the Gilberts and the Hugos were signaling that , '' he said , recalling Hurricane Gilbert that wracked the Caribbean and Hurricane Hugo that devastated South Carolina - two of the most destructive Atlantic hurricanes ever . Hurricanes have been recorded in the Atlantic every month except April , but are rare outside the hurricane season , June 1 to Nov. 30 . In this year 's season , there were 14 named storms , eight of them hurricanes . The average number of storms is nine , with about six becoming hurricanes . Usually only a couple of those storms strike the U.S. . While many of the storms spun harmlessly through the Atlantic , several caused their share of destruction . The most deadly storm was Hurricane Diana , which swept into Mexico in early August , resulting in flash floods and mudslides that killed 96 people and caused extensive damage to roads , property and agriculture , the weather service reported . A weather disturbance becomes a tropical storm , and is given a name , if its sustained winds reach 39 mph . Storms become hurricanes if winds reach 74 mph .
extractive_keyphrases: atlantic hurricane season forceful hurricanes devastating storms forecasters intense hurricanes
abstractive_keyphrases: dr. william gray below-average hurricane season