2020 has broken yet another extreme weather record: the most named tropical storms ever in an Atlantic hurricane season. 2020 is also on track to be the warmest year on record.
Theta is currently projected to move eastward, away from the United States and the Caribbean. But a prior storm, Eta, is still churning in the Gulf of Mexico and may hit Florida this week as a tropical storm.
These recent storms highlight just how busy the Atlantic has been this year. Of the 29 storm systems, 12 reached hurricane strength, and five reached Category 3 strength or higher, with winds topping 111 mph. In the United States, 12 storms made landfall, and six did so at hurricane strength. This year, there were so many storms that meteorologists ran through their entire list of official names and are now naming storms after letters of the Greek alphabet.
There were some early warning signs that 2020 would be a standout year. The National Oceanic and Atmospheric Administration anticipated that the Atlantic hurricane season would be above average back in May. But in August, they had to upgrade their forecast from between 13 and 19 named storms to between 19 and 25, and that forecast still fell short.
One key factor this year was that the Atlantic Ocean was unusually warm. Surface water needs to be at least 26°C, or 79°F, to form a hurricane, so hotter water led forecasters to conclude that more energy would be available to create storms.
Air temperatures were also warmer this year, and 2020 is currently on track to be the warmest year on record. Air can hold on to about 7 percent more water for every degree Celsius it warms up, so warmer air means more moisture is available to fuel storms.
Over the long term, humans are increasing the risks from these storms. There continues to be a lot of development in coastal areas vulnerable to tropical storms, increasing the damage tolls from the flooding and winds caused by the storms that occur.
Humanity is also changing the climate. There is a lot of variability in hurricane patterns, making it tough to figure out which factors are the most significant in shaping trends. But scientists say that as average temperatures rise, the raw ingredients for tropical storms and hurricanes amplify. Warmer water, warmer air, and higher sea levels exacerbate the damage from tropical storms, though they may not necessarily affect these events’ frequency.
Together, these factors aligned to create a record-breaking year. And more storms may still lie ahead this season, which officially ends on November 30.