Review Of The 2021 Atlantic Hurricane Season

We are now officially done with the 2021 Atlantic Hurricane Season, even though activity after October 1 has been minimal.

The 2021 Atlantic hurricane season is the sixth consecutive season with above-average activity: there were 21 named storms, 7 of which became hurricanes, and 4 of those became major hurricanes (Category 3+).

Our forecast, which was posted on March 10, called for 16 named storms, 8 hurricanes and 4 major hurricanes.

The Accumulated Cyclone Energy (ACE) ended up at about 141 percent of average. This number was slightly lower than what we forecast on March 10 (our forecast was for an ACE index of 150).

It appears that the 2021 hurricane season will probably be the fourth costliest Atlantic hurricane season, behind 2017 (1st), 2005 (2nd), and 2012 (3rd). The economic losses are expected to exceed $70 billion.

Taking a brief look at each individual impactful storm this season:

Ana formed prior to the official start of the season, on May 22 and ended up remaining in the open Western North Atlantic near Bermuda.

Bill formed in mid-June off of the southeast U.S. coast and headed out over the open ocean.

Claudette, Danny, Elsa, and Fred all made landfall on the U.S. mainland. Claudette made landfall on the coast of southeastern Louisiana on June 19; Danny made landfall on the coast of South Carolina on June 28; Elsa made landfall in the Big Bend area of northwest Florida on July 7 and Fred made landfall on the Florida Panhandle on August 16.

Grace was the season’s first major hurricane, reaching Category 3 intensity right as it made landfall in Mexico near Veracruz.
Hurricane Henri gave a significant impact to the northeastern United States when it made landfall on August 22. Henri produced record breaking rainfall in New York City and also produced widespread power outages and flash flooding across parts of New England.

The most intense of the landfalling storms was Hurricane Ida, which made landfall near New Orleans on August 29, on the 16th anniversary of Hurricane Katrina’s landfall in the same location. It was a Category 4 hurricane, reaching peak intensity right as it made landfall. Its strong winds and storm surge caused extensive catastrophic damage across southern Louisiana.
As usual, Ida’s trail of destruction didn’t end at the coastline. Three days after landfall, post-tropical cyclone Ida interacted with a mid-latitude trough and a very focused band of extreme rainfall was the result. Although the event was remarkably well-forecast days in advance, rainfall totals across Pennsylvania, New Jersey, New York State, Connecticut, Rhode Island and Massachusetts were devastating and deadly.
Ida was responsible for 115 fatalities and over $65 billion in damages from Venezuela and Colombia, then Jamaica and Cuba, and finally the United States.

Larry was a long-track major hurricane, and a named storm for 10.5 days. It clipped Newfoundland at the end of its journey on September 11, causing fairly significant damage, and rip currents associated with it killed two people in Florida and South Carolina.

Nicholas was another storm that strengthened right up to landfall. The storm made landfall near Galveston Texas on September 14 as a Category 1 hurricane.

The strongest storm of the season was Sam, which fortunately remained over water in the central Atlantic. It was a named storm for 12 days, nearly 8 of which were spent above Category 3 intensity!

If that wasn’t enough, the hurricane season unexpectedly shut down by early October. This was completely against anything that we’ve seen during a La Nina year and none of the forecast signals saw this coming. In fact, the data seemed to show the opposite and forecasted an increase in activity for the month of October, mainly based on an expected upward motion pulse of the Madden Julian Oscillation and a favorable weather pattern for development. That upward motion pulse of the Madden Julian Oscillation never happened and the favorable weather pattern for development ended up forming in the eastern Pacific instead.

Obviously, it is way too soon to really start talking about what the 2022 Atlantic Hurricane Season may bring. Be sure though that I will be monitoring the data closely and will probably start giving you an idea of my thoughts on the 2022 Atlantic Season by about February and March, 2022.