A frenetic start to the 2021 Atlantic hurricane season generated a number of destructive landfalls and major inland flooding before ending strangely quiet.
The 2021 season generated 21 named storms, the third most for any Atlantic hurricane season, behind only 2020’s record 30 storms and 2005’s 28 storms.
Nine of those storms lasted 2 days or less, which tied 2007 for the most such short-lived storms in a season, tropical scientist Phil Klotzbach noted in Colorado State University’s season wrap-up.
The entire hurricane names list for the season was used up for the second year in a row. Only this year, a new supplemental names list developed to replace Greek alphabet names wasn’t needed, as Wanda was the season’s last storm.
Despite the high number of storms, 2021’s hurricane tally (7) was right in line with the average over the past 30 years. It was only half of the nearly-record-breaking 2020 total of 14 hurricanes.
Eight of these storms made a U.S. landfall in 2021, beginning with Claudette in Louisiana in late June.
While two other landfalls were rather benign tropical storms – Danny and Mindy – the other five landfall storms were all impactful near the coast and inland, including Tropical Storms Elsa, Fred, Henri and Hurricanes Ida and Nicholas.
An incredible 19 named storms made a U.S. landfall in 2020 and 2021 combined, including eight hurricanes. One to two U.S. hurricane landfalls is considered average for a season, according to NOAA’s Hurricane Research Division.
Let’s step through the most memorable aspects of this hurricane season.
Hurricane Ida Pummeled Louisiana, Mississippi
As if Louisiana wasn’t beleaguered enough after enduring three hurricanes in 2020, Hurricane Ida roared ashore on Aug. 29, the 16-year anniversary of Katrina’s devastating landfall.
(FULL RECAP: Hurricane Ida’s Devastating Strike)
Ida pushed storm surge flooding of possibly over 10 feet in parts of southeast Louisiana and wrung out up to 16 inches of rain in southern Mississippi.
Grand Isle, Jean Lafitte, Braithwaite, LaPlace and areas near the lakeshore in New Orleans were inundated.
Jefferson Parish President Cynthia Lee Sheng said Grand Isle was “uninhabitable” after the storm, with 10 to 12 levee breaks on the Gulf of Mexico side. All of Grand Isle’s homes were damaged, and 40% of the homes were “nearly-to-completely destroyed”, according to NOAA.
Winds gusted over 100 mph along the Louisiana coast, including a 172 mph gust on a ship, among the nation’s strongest gusts ever recorded in a hurricane.
Its track brought its strongest winds into New Orleans where winds gusted up to 99 mph.
These winds downed all eight transmission lines supplying electricity to New Orleans and left some residents without power for nearly a week.
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Outages in Louisiana alone topped 1 million, and hundreds of thousands were without running water.
According to the Centers for Disease Control and Prevention, 32 were killed from Ida near the Gulf Coast, 28 of those in Louisiana. The majority of those deaths occurred in the storm’s aftermath from improper use of generators and/or carbon monoxide poisoning.
Ida’s 150 mph Category 4 landfall tied 2020’s Laura and the Last Island 1856 hurricane for strongest (by wind speed) to affect the Pelican State. It was the first time on record Category 4 landfalls occurred in Louisiana in back-to-back years.
Ida’s Historic Northeast Flood
Ida reminded us of the inland danger of tropical cyclones hundreds of miles away from a reeling Louisiana.
Even though Ida had been downgraded to a tropical depression its circulation combined with a previously-stalled front to wring out up to 11 inches of rain in the Northeast in early September.
New York City’s Central Park picked up 3.15 inches of rainfall in a single hour on the evening of Sept. 1. That was the heaviest one-hour rainfall on record there.
Newark, New Jersey, picked up 8.41 inches of rain on Sept. 1. That was their record wettest calendar day dating to 1931.
The torrential rain quickly overwhelmed major infrastructure. Roads turned into rivers that trapped motorists, subways gushed like geysers, water filled buses up to the seats and Newark Airport flooded.
Water rapidly flooded basements and ground levels in neighborhoods and apartments, trapping residents. At least 11 people in New York City died in flooded apartments alone.
According to the Centers for Disease Control and Prevention, 53 people died due to drowning in the Northeast from Ida. Twenty-eight of those drowning fatalities were in New Jersey and 18 of those were in New York.
The Schuylkill River in Philadelphia experienced its worst flood in more than 150 years on Sept. 2. Its crest of 16.35 feet was only topped by an Oct. 4, 1869 flood when the river hit its all-time record stage of 17 feet.
Twelve river gauges measured record flood crests in eastern Pennsylvania and New Jersey. After the rain ended, lingering flooding left parts of New Jersey almost unrecognizable.
If that wasn’t enough, Ida spawned destructive tornadoes. An EF3 in Mullica Hill, New Jersey, was the state’s first F/EF3-rated tornado in 31 years.
NOAA estimated Ida inflicted just under $65 billion damage in the U.S. That’s good for the fifth costliest tropical cyclone in U.S. history behind only Katrina, Harvey, Maria and Sandy.
Given the impacts, Ida will likely be retired from future use as an Atlantic named storm.
Ida Wasn’t the Only Northeast Flood
Less than two weeks before Ida’s inundating rain, Hurricane Henri lumbered off the East Coast before landfalling near the Rhode Island-Connecticut border as a tropical storm.
Henri downed trees and power lines in southern New England.
(FULL RECAP: Henri Was Mainly a Rainfall Flood Generator)
Less than a week before Henri, the remnant of Tropical Storm Fred soaked the Northeast after it triggered deadly, destructive flash flooding in western North Carolina. Fred also spawned 29 tornadoes from Georgia to Massachusetts.
And just over a month before Fred, Elsa swept through the Northeast as a tropical storm in early July with flooding rain and high winds.
That’s four storms, or their remnants, with significant impacts in the Northeast in one hurricane season.
When the Season Shut Off
A named storm formed before the official June 1 hurricane season kickoff for the seventh season in a row when Tropical Storm Ana formed the week before Memorial Day in the North Atlantic.
Elsa became the earliest-known fifth named storm on July 1, before becoming a hurricane about six weeks earlier than the usual arrival of the Atlantic’s first hurricane of the season.
A La Niña was expected to, and eventually did, develop in the fall. That usually correlates to active hurricane seasons.
During the typical peak of the season, Hurricane Nicholas made landfall along the upper Texas coast on Sept. 14. It brought flooding from storm surge and heavy rain into the storm-weary northern Gulf Coast.
But then the atmosphere invoked the mercy rule.
Nicholas wasn’t just the last U.S. landfalling storm of 2021. It was also the final landfalling storm anywhere in the Atlantic Basin this hurricane season.
Seven more storms formed after Nicholas, but they all remained over the Atlantic Ocean far removed from the mainland U.S., or most other land interests, for that matter.
It became especially quiet after long-lived, intense Hurricane Sam finally gave up its tropical identity in early October.
Only wandering Wanda, a former nor’easter, managed to become a named storm the rest of hurricane season after early October.
Why did another hectic hurricane season suddenly shut off?
First, steering winds kept Hurricanes Larry and Sam far from the U.S. mainland, curling them north, then northeast.
The typical October areas for development stretch from the western Caribbean Sea toward Florida and into the central Atlantic Ocean.
But this October, following Hurricane Sam’s demise, two factors hostile for tropical development – dry air and wind shear – set up over the very areas typically most active.
And in November, deeper plunges of the jet stream bringing colder air into the eastern U.S. also increased wind shear over these same areas.
This couldn’t have been more different than 2020.
Seven named storms, six of which became hurricanes, formed from October into November 2020. This included U.S. Gulf Coast hurricane landfalls from Delta and Zeta, and back-to-back catastrophic Category 4 Central America landfalls from Eta and Iota just 13 days apart.
The Florida Peninsula was relatively unscathed.
Elsa flirted with Tampa-St. Pete as a Cat. 1 hurricane before hitting the state’s Big Bend as a tropical storm.
Fred and Mindy each brought some winds, storm surge and rainfall flooding to the panhandle and northern Florida. But in South Florida and most of the Atlantic coast, the 2021 season was a nice respite.
Speaking of Elsa and Fred, their coastal and inland damage vaulted them into billion-dollar storms, according to NOAA, joining Hurricanes Ida and Nicholas.
Grace rapidly intensified from a tropical storm to a Category 3 hurricane in just 24 hours before it slammed into eastern Mexico in late August. It was the strongest non-U.S. hurricane landfall of the season.
Sam became the second earliest “S” storm behind only 2020’s Sally and nearly reached Category 5 status.
This resilient hurricane maintained at least Category 3 status for almost eight straight days, the longest to do so since Ivan in 2004, according to Colorado State University tropical scientist Phil Klotzbach.
Fortunately, Sam curled well away from the U.S.
Given that, the most newsworthy aspect of Sam was a major scientific breakthrough.
For the first time, scientists deployed an unmanned sail drone into the core of a major hurricane on Sept. 30. The drone encountered 50-foot waves and 120 mph winds.
Other sail drones were deployed into tropical storms Fred, Grace, Henri and Peter.
Even with the high named storm count, 2021 will forever be remembered as the season that generated Hurricane Ida.
The number of storms that triggered destructive, deadly flooding in 2021 is also a reminder that in a warming world, we can expect tropical storms and hurricanes to move slower and produce heavier rainfall.
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