The 2000 Atlantic hurricane season was a fairly active hurricane season, but featured the latest first named storm in a hurricane season since 1992. The hurricane season officially began on June 1, and ended on November 30. It was slightly above average due to a La Niña weather pattern, although most of the storms were weak. The first cyclone, Tropical Depression One, developed in the southern Gulf of Mexico on June 7 and dissipated after an uneventful duration. However, it would be almost two months before the first named storm, Alberto, formed near Cape Verde; Alberto also dissipated with no effects on land. Several other tropical cyclones—Tropical Depression Two, Tropical Depression Four, Chris, Ernesto, Nadine, and an unnamed subtropical storm—did not impact land. Four additional storms—Tropical Depression Nine, Florence, Isaac, and Joyce—minimally affected land areas.

The most significant storm of the season was Hurricane Keith, which caused extensive damage in Central America. After remaining nearly stationary offshore, Keith moved inland over the Yucatán Peninsula and later made a second landfall in Mexico at hurricane intensity. It caused $319 million (2000 USD) in damage and 40 fatalities, mostly in Belize. The precursor to Tropical Storm Leslie brought severe flooding to South Florida, which losses reaching $950 million (2000 USD). Hurricane Gordon and Tropical Storm Helene both caused moderate damage in the Southeastern United States, mainly in Florida. Tropical Storm Beryl caused minor damage in Mexico and Hurricane Debby resulted in less than $1 million (2000 USD) in damage in the Greater and Lesser Antilles. Hurricane Michael brought widespread effects to Atlantic Canada, though a specific damage toll is unknown.

Of the tropical cyclones that made landfall in the United States, none were higher than tropical storm status at the time of landfall.

Seasonal forecasts +Predictions of tropical activity in the 2000 seasonSourceDateNamedstormsHurricanesMajorhurricanesCSUAverage (1950–2000)9.65.92.3NOAAAverage1162CSUApril 7, 20001173CSUJune 7, 20001284CSUAugust 4, 20001173NOAAAugust 10, 20001173Actual activity1583

Forecasts of hurricane activity are issued before each hurricane season by noted hurricane expert Dr. William M. Gray and his associates at Colorado State University (CSU), and separately by forecasters with the U.S. Government's National Oceanic and Atmospheric Administration (NOAA). According to CSU, the average season between 1950 and 2000 had 9.6 tropical storms, 5.9 hurricanes, and 2.3 major hurricanes (storms exceeding Category 3 on the Saffir–Simpson hurricane scale). A normal season, as defined by NOAA, has 9 to 12 named storms, of which five to seven reach hurricane strength and one to three become major hurricanes.

Noted hurricane expert Dr. William M. Gray on April 7 predicted eleven named storms, with eight reaching hurricane strength and three of the eight reaching Category 3 strength. The prediction issued on June 7 was similar, increasing the named storms to twelve, eight hurricanes, and four major hurricanes. On May 10, NOAA issued a season outlook, which gave the indication of an above-average season. According to NOAA, the global scale atmospheric circulation pattern which was taking place was conducive to an above-average hurricane season. However, La Niña was present it the Eastern Pacific, which was a factor in the activity in the season. NOAA issued a 75% chance of above average activity. After the season started on June 1, CSU issued a mid-season forecast on August 4, which predicted 11 named storms, 7 hurricanes, and 3 major hurricanes. Six days after the CSU prediction, NOAA also released a mid-season outlook, forecasting exactly the same amount of activity, 11 named storms, 7 hurricanes, and 3 major hurricanes. With a 75% chance of above-average activity, there was an elevated risk of landfalling hurricanes.

Seasonal summary

The Atlantic hurricane season officially began on June 1, 2000. It was an above average season in which 19 tropical cyclones formed. Fifteen depressions attained tropical storm status, and eight of these attained hurricane status. Three hurricanes further intensified into major hurricanes. The season was above average most likely because of an ongoing La Niña in the Pacific Ocean. Three hurricanes and two tropical storms made landfall during the season and caused 77 deaths and $1.2 billion in damage (2000 USD). Hurricane Florence and Isaac and Tropical Storm Leslie also caused damage and fatalities, though none of the three made landfall. The last storm of the season, an unnamed subtropical storm, dissipated on October 29, over a month before the official end of hurricane season on November 30.

Tropical cyclogenesis first occurred in the month of June, with two tropical depressions developing in the Atlantic. However, no tropical cyclones developed in the month of July, the first phenomenon since 1993. In August, five tropical cyclones developed, most notably, Hurricane Alberto. September was more active, with seven named storms forming; that month featured Hurricane Keith, the strongest system of the 2000 Atlantic hurricane season. With seven named storms forming in September, this made it the most active September on record at the time. This record was surpassed two years later when eight storms formed in September. In addition, a quick succession of eight storms occurred in September, and lasted into early October. Six tropical cyclones existed in October and one additional subtropical storm developed in the last week of the month. Following an active October, no tropical cyclogenesis occurred in November, which is the final month of the season.

A series of six high-latitude tropical cyclones affected Europe as an extratropical cyclone, contributing to high rainfall and events across the continent in September and October 2000.

The season's activity was reflected with an accumulated cyclone energy (ACE) rating of 119. ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time, as well as particularly strong hurricanes, have high ACEs. ACE is only calculated for full advisories on tropical systems at or exceeding or tropical storm strength. Subtropical cyclones, including the unnamed storm as well as the initial stages of Florence, Leslie, and Michael, are excluded from the total.

Systems

Tropical Depression One

A tropical wave exited the west coast of Africa on May 23 and tracked westward across the Atlantic Ocean and the Caribbean. The system had entered into the Gulf of Mexico on June 6. Another tropical wave merged with the system on June 7 and developed into a low-pressure area in the Gulf of Mexico. Later that day, the National Hurricane Center began classifying the system as Tropical Depression One. Though the depression was predicted to intensify into a tropical storm, strong wind shear produced by an upper-anticyclone prevented significant strengthening.

The depression tracked slowly and erratically through the Gulf of Mexico. By late on June 8, a reconnaissance plane flight indicated that the depression had degenerated into a low-pressure area. The remnants of the depression produced gusty winds and light to moderate rainfall along the Gulf Coast of Mexico; some areas in the state of Tamaulipas reported precipitation amounts as high as . In addition, heavy precipitation was reported in south-central Texas.

Tropical Depression Two

A tropical wave emerged off the coast of Africa and quickly developed into Tropical Depression Two on June 23. Although it was well-organized, the National Hurricane Center did not initiate advisories on the depression until 1500 UTC on June 24, since it operationally appeared that a surface circulation did not exist until then. However, the depression was less organized after the National Hurricane Center began advisories. Having formed at 19.8°W, it was one of the easternmost developing tropical cyclones in the month of June, even further east than Tropical Storm Ana in 1979 and Tropical Depression Two in 2003. Though light wind shear and marginally warm sea surface temperatures were in the path of the depression, no significant intensification occurred as it tracked generally westward. The depression began encountering a stable air mass, and degenerated back into a tropical wave on June 25.

Hurricane Alberto

A well-developed tropical wave was observed in satellite imagery over central Africa on July 30. The system tracked westward and emerged into the Atlantic Ocean on August 3. Thereafter, the system rapidly organized, and developed into Tropical Depression Three at 1800 UTC that day. The depression moved west-northwestward and strengthened into Tropical Storm Alberto early on August 4. While briefly turning westward on August 6, Alberto reached hurricane status. It tracked west-northwestward, and by early the following day, the storm reached an initial peak with winds of . Shortly thereafter, Alberto re-curved northwestward. Wind shear then increased, which caused Alberto to weaken to a tropical storm on August 9. However, it quickly re-strengthened, and early on August 10, Alberto was upgraded to a hurricane again. Due to a break in a subtropical ridge, Alberto gradually curved northward and north-northeastward between August 11 and 12. While turning northeastward, Alberto strengthened into a Category 3 hurricane, becoming the first major hurricane of the season. By 1200 UTC on August 12, Alberto attained its peak intensity with winds of .

Increasing upper-level westerlies caused Alberto to weaken as it moved east-northeastward, with the cyclone losing most of its convection. Early on August 14, Alberto was downgraded to a tropical storm. A westerly trough that had been guiding Alberto outran the storm, and strong ridging developed to the north and west. As a result, Alberto turned southward on August 15, southwestward on August 16, and then to the west on August 17. While curving northwestward and then northward, Alberto began to re-strengthen, and was upgraded to a hurricane for the third occasion on August 18. Alberto reached a third peak intensity as a Category 2 hurricane with winds of on August 20. After weakening back to a Category 1 hurricane, Alberto had completed a cyclonic loop, which it had started on August 13. Due to decreasing ocean temperatures, Alberto was again downgraded to a tropical storm on August 23 as it accelerated northeastward. Six hours later, Alberto transitioned into an extratropical cyclone while centered about south-southwest of Reykjavík, Iceland.

Dakar, Senegal, received of rain as the pre-Alberto tropical wave passed over the city. Some swells were reported along the east coast of the United States a few days after the storm's recurvature. In Iceland, it was estimated that winds of at least tropical storm force were experienced there. Hurricane Alberto completed the largest loop ever observed over the Atlantic Ocean, spanning approximately 5 degrees latitude by 8 degrees longitude. The storm is currently the ninth longest-lived storm in the Atlantic Ocean (lasting 19.75 days), and is also the second longest-lived Atlantic storm during August (the longest lived is the 1899 Hurricane San Ciriaco). Also, Alberto is the farthest-travelling in the Atlantic (travelling 6,500 miles), being able to retain tropical characteristics at an unusually high latitude, up to 53˚N. The last storm to do so was Hurricane Frances in 1980.

Tropical Depression Four