The 2021 Atlantic hurricane season officially ends today. The 2021 Atlantic hurricane season produced 21 named storms (one of which was subtropical), 7 hurricanes, and 4 major hurricanes, with an Accumulated Cyclone Energy total of 145.1. This marked the Atlantic’s sixth-straight above-average Atlantic hurricane season, and the third-most active season on record in terms of named storms (behind 2020 and 2005). The average number of named storms, hurricanes and major hurricanes from 1991-2020 are 14, 7, and 3 respectively. The season was above-average due to a continuation of ongoing active Atlantic hurricane era, warm sea surface temperatures in the deep tropical Atlantic, and a developing La Niña event. The Atlantic naming list was exhausted for the second year in a row; However, barring a very unlikely post-season named storm, it appears as if the newly-created auxiliary list will not be used yet. Although the season was the third-most active on record in terms of named storms, the hurricane, major hurricane, and Accumulated Cyclone Energy totals were above average, but not extremely active. This was because of the season had many weak, short-lived storms, known by the National Hurricane Center as “shorties.” With better technology and satellites, detection of “shorties” will likely result in more frequent Atlantic hurricane seasons coming close to the end of the normal naming list.

Storm Name	NHC Classification	Formed (UTC)	Dissipated (UTC)	Maximum 1-minute sustained winds (mph)	Minimum pressure (mbar)
Ana	Tropical Storm	May 22	May 23	45	1004
Bill	Tropical Storm	June 14	June 16	65	992
Claudette	Tropical Storm	June 19	June 22	45	1004
Danny	Tropical Storm	June 27	June 29	45	1009
Elsa	Category 1 hurricane	July 1	July 9	85	991
Fred	Tropical Storm	August 11	August 17	65	991
Grace	Category 3 hurricane	August 13	August 21	125	962
Henri	Category 1 hurricane	August 16	August 23	75	986
Ida	Category 4 hurricane	August 26	September 1	150	929
Kate	Tropical Storm	August 28	September 1	45	1003
Julian	Tropical Storm	August 28	August 30	60	993
Larry	Category 3 hurricane	August 31	September 11	125	955
Mindy	Tropical Storm	September 8	September 10	45	1002
Nicholas	Category 1 hurricane	September 12	September 16	75	988
Odette	Tropical Storm	September 17	September 18	45	1005
Peter	Tropical Storm	September 19	September 23	50	1004
Rose	Tropical Storm	September 19	September 23	50	1003
Sam	Category 4 hurricane	September 22	October 5	155	929
Teresa	Subtropical Storm	September 24	September 25	45	1008
Victor	Tropical Storm	September 29	October 4	65	997
Wanda	Tropical Storm	October 31	November 7	50	987

The Atlantic began with a pre-season named storm for the seventh straight year, with Tropical Storm Ana forming in the western Atlantic on May 22. The first four months of the hurricane season were extremely active. During June, a record-tying three named storms developed. Tropical Storm Bill formed off the United States east coast on June 14, and peaked as a strong tropical storm. Tropical Storm Claudette formed just inland over southern Louisiana on June 19, making it the first storm of the 2021 Atlantic hurricane season to affect land. Tropical Storm Danny formed on June 27 and made landfall in South Carolina, the first landfalling storm of the season. The first hurricane of the season, Elsa, formed in the deep tropical Atlantic on July 1, and became a hurricane the next day near Barbados, making it the earliest hurricane in the tropical Atlantic east of the Caribbean in the satellite era on record. Elsa then made landfalls in western Cuba and northwestern Florida, causing over $1 billion in damage. Following Elsa, the Atlantic went into a month-long lull, as no tropical cyclones formed for the rest of July.

August was extremely active with 6 named storms, the most to form in August since 2012. On August 11, Tropical Storm Fred formed in the northeastern Caribbean. Fred went on make landfall in northwestern Florida, and caused severe damage in the North Carolina Appalachian mountains. Hurricane Grace formed on August 13, and made two landfalls in Mexico: one in the Yucatan Peninsula as a Category 1 hurricane, and one in Veracruz as a Category 3 hurricane. Grace was only the second major hurricane recorded in the Bay of Campeche on record. Henri formed on August 16, and briefly became a hurricane before making landfall in Rhode Island as a tropical storm, causing moderate damage. The second-strongest and most destructive storm of the season, Ida, formed on August 26 over the central Caribbean Sea. Ida made landfall in western Cuba as a Category 1 hurricane on August 27, and near Port Fourchon, Louisiana as a high-end Category 4 hurricane on August 29 with maximum sustained winds of 150 mph. Ida brought severe winds and storm surge to the eastern Louisiana coast, just one year after the similarly-strong Hurricane Laura struck the western part of the state. Ida’s extratropical remnants also caused severe damage in the northeastern United States through tornadoes and flash flooding. Ida caused an estimated $65.2 billion in damage, and the storm is blamed for over 100 total fatalities. Tropical Storms Julian and Kate formed late that month, and were weak, non-consequential storms that did not threaten land.

September was very active, with 9 named storms forming (the second-most on record, behind only 2020). 3 of those 9 storms became hurricanes, and 2 of the 3 hurricanes became major (Category 3+) hurricanes. In early September, Hurricane Larry became a Category 3 hurricane over the tropical Atlantic, and later struck Newfoundland as a Category 1 hurricane, making it the first hurricane to strike Canada since Igor in 2010. Tropical Storm Mindy formed over the northeastern Gulf of Mexico on September 8, and made landfall in northwestern Florida as a weak tropical storm. Tropical Storm Nicholas formed over the western Gulf of Mexico on September 14, and made landfall near Sargent Beach, Texas as a minimal hurricane – the second and final United States hurricane landfall of the season, and the final storm of the season to make landfall. Weak and disorganized Tropical Storm Odette formed on September 17 along the Gulf Stream, and quickly became extratropical the next day. Tropical Storm Peter formed on September 19 over the western tropical Atlantic, and remained weak east of the Caribbean without affecting land. Tropical Storm Rose formed that same day over the eastern tropical Atlantic, and was a moderate tropical storm that did not affect land. The season’s strongest and longest-lived storm and final hurricane, Sam, formed on September 22 over the central tropical Atlantic. Sam peaked as a Category 4 hurricane on September 26, with maximum sustained winds of 155 mph (just below Category 5 status) and a minimum pressure of 929 mb. No fatalities or damage were reported from Sam. Short-lived Subtropical Storm Teresa formed north of Bermuda on September 24, and dissipated the next day. Tropical Storm Victor formed over the eastern tropical Atlantic, and briefly intensified into a strong tropical storm before dissipating on October 4.

Somewhat surprisingly, tropical activity came to an abrupt end in early October. After Hurricane Sam became post-tropical on October 5, no additional hurricanes formed, and only one named storm – Wanda, a moderate tropical storm that formed from the remnants of a nor’easter that struck the Northeastern United States in late October. Wanda became post-tropical on November 7, likely ending the season. This lack of late-season activity is extremely unusual for a La Niña year. In fact, 2021 was the first La Niña year to not feature a hurricane after October 5 since 1983! 1983 was actually the least active Atlantic hurricane season in the satellite era, making the late-season inactivity even more surprising. This is in stark contrast to the 2020 Atlantic hurricane season, which had 7 named storms, 6 hurricanes, and 5 major hurricanes after September (compared to 2021’s 1 named storm, 0 hurricanes and 0 major hurricanes).

The Cyclonic Fury July forecast for the 2021 Atlantic hurricane season verified quite well: I predicted 16-21 named storms, 8-11 hurricanes, and 3-5 major hurricanes. Although the actual number of hurricanes (7) was below my forecast, my predicted Accumulated Cyclone Energy (ACE) value was extremely precise: 145 (compared to an actual value of 145.1). This is the second year in a row in which my July ACE forecast has been extremely accurate, as I predicted an ACE total of 180 last year (the actual total was 180.3!)

The 2022 Atlantic hurricane season will officially begin on June 1, 2022, though it is likely the National Hurricane Center will once again issue routine Tropical Weather Outlooks starting on May 15, 2022.