The 2021 Atlantic hurricane season, just like the 2020 season, was one for the record books – but for different reasons.
The biggest similarity was the high number of named storms. The 2021 season became only the third in history to use all of the names on the rotating seasonal list (the previous years were 2020 and 2005).
We ended the season with 21 named storms, 7 hurricanes, and 4 major hurricanes (Category 3 or higher). During an average year there would be 14 named storms, 7 hurricanes, and 3 major hurricanes. This year met or exceeded each of those categories, and it was forecast to be that way. The Atlantic hurricane season runs from June 1 to November 30.
There were four major hurricanes this season: Grace, Ida, Larry, and Sam. The strongest two were Ida and Sam, which both reached Category 4 strength. Grace and Larry peaked as Category 3 storms.
The first half of the season was off to the races – as the US was impacted by eight named storms: Claudette, Danny, Elsa, Fred, Henri, Ida, Mindy, and Nicholas.
Then, suddenly, the world’s oceans became eerily quiet. After September 25 the Atlantic and the rest of the world would struggle to produce a named storm.
That was not what meteorologists expected.
“The globe has had no major (Category 3+, max winds >=111 mph) hurricane/typhoon/cyclone formations since September 25. All other hurricane seasons in the satellite era (since 1966) have had at least two global major hurricane formations between September 26 - November 19,” Phil Klotzbach, a research scientist at Colorado State University, said in a tweet.
Both last year and this yearLa Niña conditions were observed during the last several weeks of the season, which typically favors late season tropical activity. 2020 saw three named storms in November (Eta, Theta, and Iota) and 2021 saw just one (Wanda) during the first few days.
How this hurricane season ended marks one of the biggest differences between this year and last.
Klotzbach explained that usually La Niña weakens or limits vertical wind shear, but surprisingly there was quite elevated wind shear in the Caribbean in October and November – the focal region for storms late in the season – and that led to a quiet latter part of the 2021 Atlantic hurricane season.
While an active season was predicted, it’s impossible to know in advance exactly where each storm will go and what kind of damage it may cause.
A “bad” season is all about perspective. Central American countries may consider this to have been a “good” year since not a single named storm hit any part of the region. In 2020, Central America was hit by three named storms, two of which were major hurricanes.
In the US, the state of Louisiana can’t seem to catch a break. In 2020, the Pelican State was impacted by five named storms: Cristobal, Laura, Marco, Delta and Zeta. This year the state was impacted by three named storms: Claudette, Ida and Nicholas.
In 2020 more hurricanes made landfall in the US, but this year the storms cost over $20 billion more.
Billions in damage
While only one major hurricane made landfall across the US (Ida), a total of four named storms left behind over $1 billion in damage each: Tropical Storm Elsa, Tropical Storm Fred, Hurricane Ida, and Hurricane Nicholas.
Ida alone exceeded the cost in damage of all seven billion-dollar tropical cyclones that made landfall across the US in 2020, including hurricanes like Laura, Delta, and Zeta.
“To date, Hurricane Ida is the costliest disaster this year – exceeding $60 billion,” according to the National Oceanic and Atmospheric Administration. “Ida already ranks among the top-five most costly hurricanes on record for the US since 1980.”
Ida was the strongest Atlantic hurricane of the year to make landfall with maximum sustained winds of 150 mph when it struck near Port Fourchon, Louisiana, on August 29. It was one of only three hurricanes to ever make landfall in the state of Louisiana with winds of 150 mph, the most recent being Laura from 2020.
In pictures: Ida's remnants wreak havoc in the East
“Grand Isle, Louisiana took a direct hit with 100% of its homes damaged and nearly 40% were nearly-to-completely destroyed,” according to NOAA. “There was heavy damage to the energy infrastructure across southern Louisiana causing widespread, long duration power outages to millions of people.”
In the following days the remnants of Ida moved to the Northeast and combined with a frontal system, delivering extreme rainfall rates and flash flooding, inundating streets, homes and neighborhoods.
Flash flood emergencies were declared in New Jersey and New York. At least 55 people died across New York, New Jersey, Connecticut, Maryland, Pennsylvania and Virginia.
This season’s quirks
The strongest storm of the season didn’t hit land but video was captured from inside it.
Hurricane Sam, like Ida, also reached Category 4 strength with maximum sustained winds of 150 mph. Sam remained a Category 4 hurricane for 4.5 days and generated the fifth-highest accumulated cyclone energy (ACE) recorded in the satellite era.
“ACE is integrated metric accounting for storm intensity and duration,” Klotzbach tweeted. “Sam was a long-lived, intense hurricane.”
Fortunately, unlike Ida, Sam remained out over the open waters of the Atlantic and never made landfall.
Sam’s long life, of over 11 days as a hurricane, allowed a research drone to be sailed into it, and, for the first time, to transmit video from inside a major hurricane at ocean level.
A couple of other storms made some meteorological records.
Tropical Storm Ana formed in a unique area of the Atlantic Ocean. In the last 100 years, no named storm had ever developed east of Bermuda in the month of May. Tropical Storm Ana broke that record. Typically, storms during this month form over the eastern Gulf of Mexico, western Caribbean Sea and near the southeastern US coast.
Another unique storm was Subtropical Storm Teresa. Reports of subtropical storms are not uncommon, especially in the 21st century, thanks to advanced technology. What is uncommon is for a storm to remain subtropical for its entire life, never transitioning to “tropical” status.
Teresa was also extremely short-lived, at only 24 hours. Subtropical Storm Teresa formed on Friday, September 24, at 5 p.m. Atlantic Standard Time. Exactly 24 hours later, the NHC issued its final advisory as Teresa became a remnant, low-pressure system.
Ida will likely be the only name on the retired list this year, despite there being three other major hurricanes, simply because of the amount of damage and fatalities caused. The letter “I” already has more retired names than any other letter in the alphabet.
There are already 12 retired storm names that start with the letter “I”, and Ida will likely become the 13th.
