The 1991 Atlantic hurricane season was the first season since 1984 in which no hurricanes[nb 1] developed from tropical waves, which are the source for most North Atlantic tropical cyclones.[2] The hurricane season officially began on June 1,[3] and ended on November 30.[4] It was the least active in four years due to higher than usual wind shear across the Atlantic Ocean. The first storm, Ana, developed on July 2 off the southeast United States and dissipated without causing significant effects. Two other tropical storms in the season – Danny and Erika – did not significantly affect land. Danny dissipated east of the Lesser Antilles, and Erika passed through the Azores before becoming extratropical. In addition, there were four non-developing tropical depressions. The second depression of the season struck Mexico with significant accompanying rains.
The most significant storm of the season was Hurricane Bob, which at the time was among the ten costliest United States hurricanes. After brushing the Outer Banks of North Carolina and Long Island in New York, the hurricane made landfall on Rhode Island. It caused $1.5 billion in damage (1991 USD), mostly in Massachusetts, and 17 fatalities. The strongest hurricane of the season was Claudette, which reached peak winds of 130 mph (215 km/h) near Bermuda. It passed near the island but did not cause any damage. Fabian was the only tropical storm to move over or near Cuba or Florida, producing heavy rainfall but no damage. Hurricane Grace, the final named storm of the season, provided the energy that led to the development of a powerful nor'easter known as the Perfect Storm. Originating from an extratropical storm, the Perfect Storm intensified while moving westward toward New England, leaving $200 million in damage and causing coastal damage from Puerto Rico to Florida and northward through Canada. It later transitioned into a hurricane over the Gulf Stream, finally dissipating over Nova Scotia on November 2.
Before the start of the season, hurricane expert William M. Gray released his forecast for the year's activity, a yearly practice that he began in 1984. In early April, Gray anticipated a "mild" season with fewer than ten tropical storms, of which less than six would become hurricanes.[5] Later that month, the Weather Research Center forecast ten named storms and six hurricanes, of which five would become major hurricanes while three would hit the United States.[6] In early June, Gray released an updated report that predicted the formation of eight tropical storms, four hurricanes, and one major hurricane.[nb 2][8] The revised June total was very close to the actual season activity, with the exception of forecasting one fewer major hurricane.[10] However, a later revision in August incorrectly anticipated less activity, when Gray predicted seven storms and three hurricanes.[9]