Hurricane Erin was the fifth named storm, the first hurricane, and first major hurricane of the 2001 Atlantic hurricane season. Erin formed as a tropical depression on September 1. The depression quickly became Tropical Storm Erin. Erin moved west-northwest and degenerated into a tropical wave on September 5, because of strong upper-level wind shear. The next day, Erin's remnants re-organized and on September 9, Erin strengthened into a hurricane as it moved northwest. This was the latest date for a hurricane in the Atlantic basin since Hurricane Diana of 1984. Late on September 9, Erin reached its peak of 120 mph winds and a pressure of 968 mb, a Category 3 hurricane on the Saffir-Simpson Hurricane Scale. At its closest approach, Erin passed 105 miles east-northeast of Bermuda near peak intensity, and subsequently weakened as it turned to the east. An approaching trough caused Erin to move northeast and out to sea, and after passing just east of Cape Race, Newfoundland, Erin became extratropical on September 15. Erin's extratropical remnants continued northeast towards Greenland, and Erin lost its identity near there on September 17.
Erin caused no known damage, and no fatalities.
|Formation||September 1, 2001|
|Dissipation||September 15, 2001|
|Highest winds||120 mph|
|Lowest pressure||968 mbar|
|Areas affected||East Coast of the United States, Bermuda, Atlantic Canada|
On August 30, a tropical wave exited the coast of Africa. The wave almost immediately showed signs of organizing into a tropical cyclone, with deep convection and rainbands associated with it. The wave continued to organize and late on August 30, Dvorak classifications began on the wave. After passing well to the south of the Cape Verde Islands on August 31, the wave stopped its organization trend, as convection became sporadic. The wave became poorly-organized as it moved westward at a swift foward speed of 20 mph. Despite the poor organization, environmental conditions favored intensification. On September 1, the cloud pattern became better organized, and a low-level circulation center quickly developed within the wave. Following an increase in convection and confirmation of a closed surface circulation near a buoy, it is estimated the wave became Tropical Depression Six on September 1, while located 1600 miles east of the Lesser Antilles. After forming, the depression moved west-northwest due to a ridge of high pressure to its north. With weak to moderate upper-level wind shear, the wave quickly intensified, and became Tropical Storm Erin early on September 2. Although Erin had well-established upper-level outflow and developing convection near the center, its inner core remained ill-defined. Erin continued west-northwest, slowly strengthening to reach an initial peak of 60 mph winds while located about 1150 miles east of the Lesser Antilles.
Because of favorable conditions that were expected to persist, Erin was forecast to reach 85 mph winds and become a hurricane. However, an upper-level low northwest of the storm produced strong vertical wind shear over Erin, and as a result, Erin quickly weakened, with the low-level circulation becoming exposed on the southwest side of the deep convection. On September 4, the shear eased somewhat, which allowed Erin to briefly re-strengthen. However, Erin remained disorganized and following an increase in southwesterly wind shear, Erin started to weaken. On September 5, Erin weakened to a tropical depression and hours later, its circulation dissipated. This caused Erin to degenerate into a tropical wave. The remnants of Erin moved west-northwest and on September 6, the wave gradually produced deep convection. A surface circulation redeveloped in the northern portion of the wave and because of this, Erin became a tropical depression again late on September 6, while located 365 miles north-northwest of where it previously dissipated. Erin moved north-northeast, then turned north-northwest, strengthening back into a tropical storm on September 7. Erin steadily intensified, and its convective pattern became much better organized on September 8. On September 9, Erin became a hurricane, when a 40 mile wide eye developed. On September 9, Erin continued to rapidly intensify, reaching winds of 120 mph late that day, becoming a Category 3 hurricane on the Saffir-Simpson Hurricane Scale.
Shortly after peaking, Erin passed 105 miles east-northeast of Bermuda, which was its closest approach to the island. Erin maintained peak intensity for 18 hours before weakening, albeit slowly. Erin weakened slower than usual because of warmer than usual water temperatures. Late on September 10, Erin weakened to a Category 2 hurricane. Multiple shortwave troughs eroded the western portion of the subtropical ridge and caused Erin to decelerate on September 11 as it turned to the east. A strengthening mid to upper-level trough over Canada caused Erin to move northeast and out to sea. Erin gradually accelerated northeast and on September 15, Erin weakened to a tropical storm and passed just east of Cape Race, Newfoundland. Erin's convection gradually diminished as it moved northeast and late on September 15, Erin became an extratropical cyclone. Erin's extratropical remnants continued northeast and after crossing over southern Greenland, Erin merged with a high-latitude cyclonic flow east of Greenland on September 17.
Hurricane Erin south of Nova Scotia.
In Bermuda, a Hurricane Watch was issued, as Erin posed a threat to the island. Around 24 hours before Erin made its closest approach to the island, the watch was upgraded to a Hurricane Warning. Initially, forecasters predicted Erin would pass within 15 miles of the island. Because of this, ferry and bus transport was suspended. Officials prepared a school to be used as an emergency shelter, although few people actually used it. Because of Erin, several flights in and out of Bermuda were cancelled, which stranded hundreds of travelers. Also, cruise ships and cargo ships delayed or cancelled their arrivals.
A closeup view of Erin's eye.
Swells from Erin caused rip currents along the North Carolina coastine. Also, waves were expected to reach 6 feet. The National Hurricane Center advised authorities and residents to monitor the rough seas.
In Bermuda, Erin's strongest winds remained east of the island. As a result, winds of only 41 mph occured. The winds downed several trees onto power lines, which left dozens of homes without power for several hours. In addition, prolonged periods of high waves caused beach erosion. Also, the waves broke a boat from its moorings, but the two men swam through the rough seas in order to prevent the boat from running aground. Erin produced rainfall on the island, but no flooding was reported. Little structural damage occured on the island, and no deaths or injuries were reported.
Erin produced sustained winds of 53 mph with a wind gust of 67 mph in Newfoundland, namely at Cape Race. Also, Erin produced heavy rainfall, peaking at 5.1 inches at Sagona Island. Along the coast, the passage of Erin resulted in waves as high as 30 feet, while an offshore buoy reported waves as high as 47 feet. No damage occured in Atlantic Canada from Erin, nor did any deaths.
Lack of Retirement
Because there was minimal damage, the name Erin was not retired in the Spring of 2002 by the World Meteorological Organization. It was used again during the 2007 Atlantic hurricane season.