The Unofficial Start of the 2021 Atlantic Hurricane Season

Photo by NASA on Unsplash

Hurricanes, as depicted in the satellite image above, can be found all over the world and are known by many names depending on one’s location in the world (typhoons in the Northwest Pacific and cyclones in the Indian and South Pacific Oceans.) The North Atlantic Ocean usually sees an annual slew of hurricanes between the months of June and November, most of which are rather benign, but some have the potential to be catastrophic.

This past weekend, the first named storm of the year formed—a harbinger of the annual Atlantic hurricane season which runs from June 1st to November 30th each year. Subtropical Storm Ana formed on Saturday off the coast of Bermuda, but was upgraded to Tropical Storm Ana early Sunday morning as a result of shifting and intensifying winds. 

The National Hurricane Center (NHC) also monitored an area of low pressure in the western Gulf of Mexico near Texas, although it has since moved inland and did not become a named storm. 

But Tropical Storm Ana in particular was rather unusual, as it originated in an area of the Atlantic that does not usually see storms in May. Most “pre-season” storms originate over the Gulf of Mexico or Carribean Sea, but not near Bermuda. Tropical Storm Ana ended up having maximum wind speeds of 40mph (far short of the 74mph needed for a hurricane classification), but was also moving northeast and did not make landfall. Although Ana dissipated less than 18 hours after being upgraded to tropical status, the storm serves as a warning for the many more intense storms to come in the 2021 Atlantic hurricane season.

You may have noticed, however, that the hurricane season starts on June 1st, but Tropical Storm Ana formed over a week before that on May 22nd. That is partly the reason for the ongoing debate about whether or not the hurricane season start date should be earlier, as storms have been named before the official start of the season in the past 7 consecutive years. “History tends to repeat itself,” they say, and that could not be more true with the annual Atlantic hurricane season. 2020 was quite a year to behold with COVID-19 and worldwide shutdowns, but an often unacknowledged event was its hurricane season. With a total of 30 named storms, it became the year with the most named storms on record, and had to borrow names from the Greek alphabet after exhausting the predetermined 21 name list. In September of 2020, conditions in the Atlantic managed to result in 5 active hurricanes all happening at once. 

Despite this, scientists are predicting that the 2021 season will be less intense, have less storms, and cause less damage. Nevertheless, as Ben Friedman, the administrator of the National Oceanic and Atmospheric Administration (NOAA) said, “It only takes one storm to devastate a community.” 

Current estimates for the 2021 Atlantic hurricane season say there could be anywhere from 13 to 20 named storms, 6 to 10 hurricanes (74mph or above), and 3 to 5 major hurricanes (111mph or above.) 

Especially during the last few decades, scientists have started to notice that larger and deadlier hurricanes are on the rise. A study found that sea-level rise linked to human activity resulted in an extra $8 billion of damages during Hurricane Sandy. In the Atlantic this year, NOAA scientists are predicting warmer sea temperatures and weaker trade winds, which can both lead to the variable weather patterns that tropical storms and hurricanes arise from. 

Much of the scientific community is now confident that climate change is to blame for the increase in powerful storms, as it seems that the warmer the water temperature of the water is, the greater the amount of water vapor in the air, which leads to heavier rainfall, larger floods, and ultimately more damage to coastal communities. However, there is still debate over just how much climate change plays a role in these weather trends. Some scientists say that the varying intensity of storms are due to natural variability and a cycle of ocean warming/cooling known as the Atlantic Multidecadal Oscillation. El Niño and La Niña have also come up a fair number of times in the argument for this as a naturally occurring process.

Although the proportion of severe storms has increased, the overall number of storms has stayed relatively the same (2005 saw 28 named storms, which stood an unbroken record for 15 years.) Researchers say that climate change may be causing hurricanes to weaken more slowly after landfall, increasing their destructive abilities, and stretching out their damage over longer periods of time. Scientists have observed a 41% increase in the amount of rainfall as storms move over land. Additionally, more and more storms are having northerly trajectories, putting more communities along the US east coast at risk.

Climate change is almost certainly responsible for part of the increased storm intensity that can be seen today. And although estimates say that this season will not be as devastating, they are just that, estimates. Only time will tell if the upcoming season turns out to be more or less extreme than 2020.

References:

New York Times - Breaking News Article:

https://www.nytimes.com/2021/05/22/us/ana-storm.html

New York Times - Prediction Article:

https://www.nytimes.com/2021/05/20/climate/atlantic-hurricane-outlook.html

NPR Article: https://www.npr.org/2021/05/22/999461806/subtropical-storm-ana-is-first-named-storm-of-atlantic-hurricane-season

NOAA Article:

https://www.noaa.gov/media-release/noaa-predicts-another-active-atlantic-hurricane-season

CNN Article: 

https://www.cnn.com/2021/05/22/weather/ana-tropical-storm-atlantic-hurricane-season/index.html