The 2021 Atlantic hurricane season officially ended Tuesday, and it was a busy one.
A total of 21 named storms developed (winds of 39 mph or greater), including seven hurricanes (winds of 74 mph or greater), of which four were major hurricanes of Category 3 or higher (winds of 111 mph or greater). This above-average season was accurately predicted by the National Oceanic and Atmospheric Administration’s Climate Prediction Center, a division of the National Weather Service, in its May and August outlooks.
“NOAA provided the science and services necessary to protect life and property before, during and after storms all season long,” NOAA Administrator Rick Spinrad said in a news release. “From essential observations to advanced warnings to critical response actions, NOAA supports communities so they are ready, responsive and resilient to the impact of tropical cyclones each and every hurricane season.”
Stacking up
This year was the third most active year on record in terms of named storms. It marks the sixth consecutive above-average Atlantic hurricane season and this was the first time on record that two consecutive hurricane seasons used all 21 storm names on the primary list.
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Scientists attributed the elevated activity in recent years to the warm phase of the Atlantic Multidecadal Oscillation (AMO) that began in 1995, favoring more, stronger and longer-lasting storms. Scientists believe the AMO is driven by a combination of internal climate variability and changes over time in small airborne particles, often referred to as aerosols, over the North Atlantic.
Additionally, the Intergovernmental Panel on Climate Change’s Sixth Assessment Report, released in August, projected with high confidence that the global proportion of tropical cyclones that reach very intense levels (category 4 or 5), along with their peak winds and rainfall rates, will increase with climate warming at the global scale.
This season’s storm activity started early and quickly ramped up and it was the seventh consecutive year with a named storm forming before the official start to the season on June 1. Elsa became the earliest fifth-named storm on record for any given season, forming on July 1. This broke Eduardo’s record, which became a named storm on July 6, 2020.
According to Matthew Rosencrans, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, “Climate factors, which include La Nina, above-normal sea surface temperatures earlier in the season and above-average West African monsoon rainfall were the primary contributors for this above-average hurricane season.”
Hurricane Ida, which made landfall as a massive Category 4 storm in Louisiana in late August, caused an estimated $64.5 billion in damage, NOAA reported. Ida was so costly that it surpassed the estimated cost of all of the previous year’s hurricanes combined.
NOAA added that, in total, this year’s hurricane season was estimated to have caused about $70 billion in damages and killed more than 160 people.
Hurricane research and observations
Scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory successfully deployed five new extreme weather Saildrones to collect data at the ocean-atmosphere interface in the Caribbean and western tropical Atlantic. One uncrewed Saildrone captured the first-ever video and measurements on the ocean surface during a major hurricane, withstanding 125-mph winds and 50-foot waves during Hurricane Sam.
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Saildrone data, combined with data from other NOAA aircraft and NOAA satellites, has helped forecasters make accurate storm predictions and has helped hurricane researchers to achieve a better understanding of storm processes, which ultimately improves their forecast models. NOAA officials said the improved data led to an accurate forecast of Hurricane Ida, which tied for the fifth-strongest hurricane to ever make landfall in the U.S., devastating portions of the South and Northeast.
Looking ahead
The 2022 hurricane season will officially begin on June 1. NOAA’s Climate Prediction Center will issue its initial seasonal outlook in May, but now is the time to make sure your family is weather ready by preparing for the season ahead.
Click here for more FreightWaves articles by Nick Austin.
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