The season officially lasted from June 1, 2001, to November 30, 2001, dates which by convention limit the period of each year when tropical cyclones tend to form in the Atlantic Ocean basin.

[9] On December 7, 2000, Gray's team issued its first extended-range forecast for the 2001 season, predicting above-average activity (13 named storms, 8 hurricanes, and about 4 of Category 3 or higher).

The increase in the forecast was attributed to the warm sea surface temperatures, although the agency noted that the season would likely not be as active as previous ones due to the effect of a weak to moderate El Nino.

Another, Hurricane Michelle, attained the lowest barometric pressure of any storm that year, at 933 mbar (27.55 inHg), and cut a path of destruction across Cuba on November 4.

Overall, Allison caused about $8.5 billion in damage (2001 USD), making it the costliest and second-deadliest tropical storm on record in the United States.

Moving westward, the system displayed signs of a weak low-level circulation beginning on July 10, and after deep convection formed on the following day, a tropical depression developed around 18:00 UTC about 1,150 mi (1,850 km) east of the Windward Islands.

The storm weakened to a tropical depression over southern Alabama about seven hours later, before degenerating into a remnant low over Mississippi early on August 7.

Moving generally westward, the wave organized into a tropical depression about 1,500 mi (2,400 km) east of the Windward Islands on August 14.

However, after reaching the southeast Caribbean, a circulation re-developed while the system was situated 290 mi (470 km) south of Saint Croix on August 17.

After crossing the Virgin Islands and entering the Atlantic, strong wind shear caused Dean to degenerate into an open tropical wave near the Bahamas on August 23.

Located over warm waters and in an area of favorable conditions, Dean steadily strengthened while moving to the northeast and peaked just below hurricane status on August 28.

There, up to 12.7 in (320 mm) of precipitation fell in Salinas, causing widespread flooding in the eastern and southern portions of the main island.

By early the next day, the depression intensified into Tropical Storm Erin and reached an initial peak with winds of 60 mph (97 km/h) on September 3.

[29] Tropical cyclone warnings and watches were issued for Bermuda beginning on September 8, which were discontinued two days later after the storm bypassed the island.

After weakening slightly, Gabrielle emerged into the Atlantic near Titusville on September 15, accelerated to the northeast, and strengthened, becoming a Category 1 hurricane two days later.

[33] Hurricane Gabrielle produced moderate winds along coastal areas of western Florida, reaching 58 mph (93 km/h) at Venice.

[34] Gabrielle brushed the eastern coast of Newfoundland; the rainfall set the all time six-hour precipitation record at St. John's, with a total of 3.54 in (90 mm).

The wave moved generally westward across the Atlantic and organized into Tropical Depression Eleven approximately 90 mi (145 km) southeast of Barbados on October 4.

Around 02:00 UTC on October 9, the hurricane made landfall near Monkey River Town, Belize, with peak winds of 145 mph (233 km/h).

[41] Although Iris's circulation dissipated, its remnants contributed to the development of Tropical Storm Manuel in the eastern Pacific Ocean on October 10.

[42] Rainfall from the outerbands of Iris caused flooding in the Dominican Republic, resulting in the evacuation of 35 families after rivers exceeded their banks.

[45] Iris caused 24 deaths in Belize – with 20 occurring when the dive boat Wave Dancer capsized near Big Creek – and at least $250 million in damage.

Continuing westward due to a ridge to it north, Jerry strengthened further as it approached the Lesser Antilles, reaching peak winds of around 50 mph (80 km/h).

As Jerry entered the eastern Caribbean Sea early on October 8 after bypassing St. Vincent, its forward speed increased to 25 mph (40 km/h).

Jerry continued to deteriorate, and later on October 8, aircraft data indicated the system had weakened into a broad area of low pressure with scattered squalls mainly to the east of the remnant center.

Michelle made landfall in Cuba twice, first on Cayo Largo del Sur with peak winds of 140 mph (230 km/h) and then on the mainland near the Bay of Pigs at a slightly weaker intensity.

Operationally, the storm was considered a non-tropical low, and the National Hurricane Center did not begin issuing advisories until it became a tropical cyclone.

As a result of a ship reporting hurricane-force winds near the center, and due to the development of a weak mid-level warm core, the subtropical cyclone was reclassified as Hurricane Noel on November 5.

Increasing westerly wind shear limited convection near the center, and Noel weakened to a tropical storm early on November 6.

[68] Progressively cooler water temperatures contributed to weakening,[69] and Noel became extratropical later on November 6 about 330 mi (530 km) southeast of Newfoundland.