The 2021 hurricane season is already off to a record start in the United States. To date, five named storms have formed in the Atlantic — including Hurricane Elsa, which became a hurricane July 2, the earliest fifth-named Atlantic hurricane since 1966. Elsa made landfall July 7 in the Florida Panhandle as a Category 1 storm.
Now halfway through the hurricane season, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center released its annual mid-season update Aug. 4, suggesting conditions are ripe for another above-average number of storms. The agency is predicting a busy, but not record-breaking, season with 15 to 21 named storms (winds of 39 mph [62 kph] or greater). That includes seven to 10 hurricanes, three to five of those Category 3, 4 or 5.
NOAA's May 2021 Atlantic Hurricane Season Outlook predicted 13 to 20 named storms, with six to 10 of those hurricanes. Meteorologists analyzed a mix of atmospheric and oceanic conditions when updating the original forecast.
"After a record-setting start, the 2021 Atlantic hurricane season does not show any signs of relenting as it enters the peak months ahead," NOAA administrator Rick Spinrad, Ph.D., said in a press statement.
What Do Hurricane Categories Mean?
According to the Saffir-Simpson scale:
- Category 1 storms have sustained winds of 74 to 95 miles (33 to 42 kilometers) per hour.
- Category 2 storms have sustained winds of between 96 to 110 miles (154 to 177 kilometers) per hour.
- Category 3 storms have sustained winds of 111 to 129 miles (178 to 208 kilometers) per hour. Damage to homes can be major.
- Category 4 storms have sustained winds of 130 to 156 miles (209 to 251 kilometers) per hour. Property damage can be extensive.
- Category 5 storms have sustained winds of 157 miles (252 kilometers) per hour or higher. Damage will be widespread and catastrophic.
La Niña's Back?
In July, NOAA declared a La Niña watch, which means there is a potential for La Niña to develop during the 2021 hurricane season.
"La Niña occurs when there are cooler than average sea surface temperatures in the equatorial region of the Pacific Ocean, and a corresponding atmospheric signal," Matthew Rosencrans, NOAA's lead hurricane season forecaster, said during an Aug. 4 news conference. "La Niña is linked to weakening wind shear over the Caribbean and tropical Atlantic Ocean, which favors more and stronger Atlantic storms."
Rosencrans said reduced vertical wind shear and a favorable west Africa monsoon are both signals for above average seasonal activity.
While conditions suggest 2021 will be a busy season, Rosencrans said he doesn't believe it will be as active as the record-breaking 2020 season because Atlantic sea surface temperatures aren't expected to be as warm — and so far are trending closer to average.
NOAA's update to the 2021 outlook covers the entire six-month hurricane season, which runs from June 1 until Nov. 30. The hurricane season peaks in mid-August through October, though the tropics have been quiet during the past few weeks.
The Calm Before the Storm
But don't confuse the quiet period for a quiet season. In fact, Rosencrans said the quiet period didn't impact the updated number of projected storms for the remainder of the season.
"We had such a fast start to the season and made it to the earliest fifth named storm, so normally, during June and July, we only have two named storms," he said. "[We're at] five this year, so we're already ahead of the pace. So, the 'quiet period' kind of just brought us a little bit closer to normal."
And while NOAA and the Climate Prediction Center can forecast all they want, it's the National Hurricane Center that tracks storms that actually form and predicts their paths. And the best track of a storm can be made only about five to seven days out. That's why people living along the coast, and in low-lying areas and regions prone to inland flooding, need to be prepared.
"As we have seen in recent years, threats from hurricanes are not limited to damaging winds but also dangerous storm surge and torrential rain and wind flooding," Rosencrans said. "Everyone should know their hurricane risk, have a plan and be prepared for the upcoming core of the season."
"Now is the time for families and communities to ensure their preparations are in place," National Weather Service Director Louis W. Uccellini, Ph.D., said in a press statement. "These storms can be devastating, so be prepared for all possible outcomes by staying tuned to the forecast and following safety information and possible evacuation notifications issued by emergency officials."