Animated satellite imagery of the named storms that occurred during the 2020 Atlantic Hurricane Season from May 13 through Nov. 18. Video: NOAA Satellites
Though the record-breaking 2020 Atlantic hurricane season officially ends Monday, tropical storms may develop well past that day.
The 2020 season, officially June 1-Nov. 30, produced 30 named storms, with top winds of 39 mph or greater. Of those, 13 became hurricanes with top winds of 74 mph or greater, including six major hurricanes with top winds of 111 mph or greater.
This is the most storms on record, surpassing the 28 from 2005, and the second-highest number of hurricanes on record, according to the National Oceanic and Atmospheric Administration. Additionally, this is the fifth consecutive year with an above-normal Atlantic hurricane season, with 18 above-normal seasons out of the past 26. An average season has 12 named storms, six hurricanes, and three major hurricanes.
“Throughout this relentless hurricane season, NOAA worked around-the-clock to provide critical data and reliable forecasts to our Nation’s communities in the path of devastating storms,” said U.S. Secretary of Commerce Wilbur Ross in a statement. “The services provided by NOAA, alongside our emergency management partners, undoubtedly helped save many lives and protect property.”
There were a record nine named storms from May through July. Tropical Storm Wilfred formed on Sept. 18, using the last of the 21-name Atlantic list. For the second time in history, the Greek alphabet was used for the remainder of the season, extending through the ninth name in the list, Iota.
“The 2020 Atlantic hurricane season ramped up quickly and broke records across the board,” said Neil Jacobs, acting NOAA administrator. “Our investments in research, forecast models, and computer technology allowed forecasters at the National Weather Service, and its National Hurricane Center, to issue forecasts with increasing accuracy, resulting in the advanced lead time needed to ensure that decision makers and communities were ready and responsive.”
The increased hurricane activity is attributed to the warm phase of the Atlantic Multi-Decadal Oscillation, or AMO, which began in 1995, and has favored more, stronger, and longer-lasting storms since that time. Such active eras for Atlantic hurricanes have historically been 25 to 40 years. The AMO is a series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes.
NOAA seasonal hurricane predicted a high likelihood of an above-normal season with a strong possibility of it being extremely active, according to officials.
“As we correctly predicted, an interrelated set of atmospheric and oceanic conditions linked to the warm AMO were again present this year,” said Gerry Bell, Ph.D, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center. “These included warmer-than-average Atlantic sea surface temperatures and a stronger west African monsoon, along with much weaker vertical wind shear and wind patterns coming off of Africa that were more favorable for storm development. These conditions, combined with La Nina, helped make this record-breaking, extremely active hurricane season possible.”
Scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory and the Satellite Data and Information Service were able to get wave height information into the hands of forecasters using new instrumentation like the Ka-band Interferometric Altimeter. This vital oceanic data allowed forecasters to help mariners avoid dangerous situations at sea.
The 2021 hurricane season will officially begin on June 1 and NOAA’s Climate Prediction Center will issue its initial seasonal outlook in May.