1991 Atlantic hurricane season
The 1991 Atlantic hurricane season officially began on June 1, and ended on November 30. It was the least active in four years due to higher than usual wind shear across the Atlantic Ocean. No hurricanes developed from tropical waves, which are the source for most North Atlantic tropical cyclones. There were no tropical storms in the Gulf of Mexico for only the third time in the 20th century, after 1927 and 1962.
About 1991 Atlantic hurricane season in brief
The 1991 Atlantic hurricane season officially began on June 1, and ended on November 30. It was the least active in four years due to higher than usual wind shear across the Atlantic Ocean. No hurricanes developed from tropical waves, which are the source for most North Atlantic tropical cyclones. The strongest hurricane of the season was Claudette, which reached peak winds of 130 mph near Bermuda. The most significant storm was Hurricane Bob, which at the time was among the ten costliest United States hurricanes. There were no tropical storms in the Gulf of Mexico for only the third time in the 20th century, after 1927 and 1962. The season produced twelve tropical depressions, which was the lowest in five years. Four of the storms developed into hurricanes, although for the first time in over 24 years, none of the hurricanes originated from tropical Waves. The first storm of the year was Ana, which originated from a cold-core that persisted east of Jacksonville, Florida, by June 25. The system moved in a clockwise direction around an anticyclone system located over Florida, exceeding the clockwise motion of the system by around 25 minutes. The final named storm was Grace, which provided the energy that led to the development of a powerful nor’easter known as the Perfect Storm. The Perfect Storm intensified while moving westward toward New England, leaving USD 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.
The season’s activity was reflected with a low cumulative accumulated cyclone energy (ACE) rating of 36, a measure of the power of the last hurricane that existed, broadly speaking, as well as the strong storms that last a long time. The ACE rating is only calculated for full advisories on tropical systems at or above 34 knots or tropical storm strength, officially called subtropical cyclones or storm cyclones, officially known as storm-force winds or storm-strength advisories. In most seasons, the majority of storms develop from tropical wave. From late April to late November, there were 73 tropical waves that exited the west coast of Africa. The total was higher than average, although many of them were poorly defined and had little thunderstorm activity. The waves traversed the Atlantic ocean further south than normal, typically not becoming convectively active until moving across northern South America. This was partially due to decreased tropical cyclogenesis from African tropical waves. There were also low rainfall amounts across the Sahel, which is the source of most tropical cyclone activity in the Atlantic. In addition, only three of the eight tropical storms were from tropical storms, and none had the characteristics of a Cape Verde-type hurricane. Fabian was the only tropical storm to move over or near Cuba or Florida, producing heavy rainfall but no damage. It later became an extratropical storm.