An “extremely active” hurricane season was predicted—and it broke records! See the latest on the historic 2020 hurricane season, including how the forecasts held up to reality. Also, find your common questions and answers about Earth’s most violent storms!
2020 Atlantic Hurricane Season Breaks Records
The arrival of the 29th named storm of the season, Tropical Storm Theta, officially made the 2020 Atlantic Hurricane Season a record-breaking one. (Then the record was promptly broken again by Hurricane Iota, bringing the season’s total to 30.) Let’s review what happened in the busiest season in the 169-year history of record-keeping.
What Happened This Season?
Officially, the Atlantic hurricane season lasts from June 1 to November 30 and covers the Atlantic Basin—the area encompassing the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico.
However, on May 16, 2020—approximately two weeks prior to the official start of the eason—Tropical Storm Arthur became the first named storm of the year. (Starting early is not unusual. This marks the 6th consecutive year that storms have formed prior to June 1.)
Predictions from earlier this year called for an extremely active season and the number of observed storms has well-exceeded those forecasts. By September 18, the hurricane season had already gone through the usual alphabetical list of 21 names, ending with Wilfred. For only the second time since this system has been in use, we moved to the Greek alphabet, starting with Alpha (also on the 18th of September) and ending with Iota on November 18.
As of the end of the 2020 Hurricane Season, there have been 30 named storms:
- 13 hurricanes (6 major)
- 15 tropical storms
- 2 subtropical storms
A record six hurricanes made landfall in the U.S., many bringing severe flooding—especially in Louisana and other Gulf Coast states which got hit by three hurricanes in a row (Hurricane Laura, Hurricane Delta, and Hurricane Zeta),
With the formation of Subtropical Storm Theta on November 10, the 2020 season became the most active season on record, with 29 named storms having formed. Three days later, with the appearance of Hurricane Iota, that record was smashed once again.
- The previous record (28 storms) was set in 2005—a season that included the infamous hurricanes Katrina and Wilma.
- Prior to that, the season with the most storms was that of 1933, with 20 named storms.
The 2020 Hurricane Forecast
The official Atlantic hurricane season lasts from June 1 to November 30 (though hurricanes can certainly happen at any time). Forecasts cover the Atlantic Basin—the area encompassing the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico.
Each year, a series of hurricane forecasts are issued from April through August by the noted hurricane experts at the Department of Atmospheric Science at Colorado State University (CSU). Additional forecasts are put out by the National Oceanic and Atmospheric Administration (NOAA).
When it comes to hurricanes, there are many indicators related to atmospheric and oceanic conditions that indicate what to expect. Keep in mind: Whatever the forecast, remember that it only takes one hurricane to make landfall and coastal residents should prepare for every hurricane season.
Below is information from CSU’s hurricane season forecasts. (The final CSU hurricane forecast was released in early August.)
What Was the 2020 Hurricane Season Outlook?
- An “extremely active” hurricane season was predicted. The main reasons for this stronger-than-usual forecast:
- El Niño climate conditions, which tend to suppress hurricane activity, were predicted to weaken to either a cool neutral El Niño or a weak La Niña during late summer. This typically results in increased storm activity in the Atlantic.
- In the tropical Atlantic, sea surface temperatures were much warmer than normal, which tends to be associated with stronger storms. In the subtropical Atlantic, temperatures are much warmer than average.
- Above-normal probability of major hurricanes striking the U.S. coastline was also predicted.
- The last forecast from Colorado State University gave a 74% chance of a major (Category 3 or greater) hurricane making landfall along the entire coast of the continental U.S., a 49% chance along the East Coast and Florida peninsula, a 48% chance along the Gulf Coast, and a 63% chance in the Caribbean. These probabilities are roughly 15% above the averages for the last century.
Credit: Petrovich9/Getty Images
How Many Hurricanes Were Expected This Year?
Overall, an above-average number of storms was expected in 2020, making for an “extremely active” season:
- CSU’s last forecast (published August 5, 2020) predicted a total of 24 named storms (average is 12.1) for the year, of which 12 would become hurricanes (average is 6.4). Of the hurricanes that were expected to occur, 5 would turn into major hurricanes (average is 2.7). Major hurricanes are storms reaching at least Category 3 strength in the Saffir-Simpson Hurricane Scale.
- NOAA’s initial forecast (published May 21, 2020) predicted a 60% chance of an “above-normal” season made up of between 13 and 19 named tropical storms. Of those storms, between 6 and 10 were likely to become hurricanes, and between 3 and 6 of those hurricanes could have become major hurricanes (category 3, 4, or 5). Read NOAA’s forecast here.
Observed Storm Activity
|Named Storm Days||80||85||100||118||59.4|
|Major Hurricane Days||9||9||11||8.75||6.2|
|Accumulated Cyclone Energy||150||160||200||180||106|
|Net Tropical Cyclone Activity||160%||170%||215%||225%||116%|
|Activity Level||Above average||Well above average||Extremely active||Extremely active||–|
*Number included already-formed storms Arthur, Bertha, Cristobal, Dolly, Edouard, Fay, Gonzalo, Hanna, and Isaias.
2020 Hurricane Names
See this year’s list of hurricane names for both the Atlantic Basin and Eastern North-Pacific. Is your name listed? The World Meteorological Organization’s Hurricane Committee chooses these names (not The Old Farmer’s Almanac!).
The list actually repeats every six years unless a storm is so severe that the World Meteorological Organization votes to retire that name from future lists. See more about how hurricanes get their names.
More than 60 names have been retired since 1950 because they resultd in significant property damage or deaths. A name can be retired at the request of a country affected by the storm. See the most recent list of retired hurricane names.
2019 Hurricane Season Summary
Overall, the 2019 hurricane season had slightly more storm activity than expected, with more named tropical storms than normal, but a near-average number of hurricanes. September was a considerably more active month than predicted, as was October, while August saw very little storm activity.
The most intense storm of the 2019 season was Hurricane Dorian, which struck the Bahamas as a Category 5 hurricane in early September. It was the costliest storm in Bahamian history, leaving behind $3.4 billion in damage and killing at least 74 people, though many more are still missing. Dorian then continued northward, weakening to a Category 1 hurricane before striking the coast of North Carolina and, later, Atlantic Canada.
Read more about last year’s season in the full CSU 2019 hurricane report.
Initial 2019 Forecast
Final 2019 Forecast
Observed Storm Activity
|Named Storm Days||50||55||68.5||60.1|
|Major Hurricane Days||4||5||10||3.9|
|Accumulated Cyclone Energy||80||105||130||92|
|Net Tropical Cyclone Activity||90%||110%||142%||103%|
|Activity Level||Slightly below-average||About average||Slightly above-average||–|
Facts About Hurricanes
Q. What Is a Hurricane?
A. A hurricane is a tropical storm with winds that have reached a constant speed of at least 74 mph in the North Atlantic Ocean, Caribbean Sea, or Gulf of Mexico. A hurricane’s winds blow in a large spiral around a relatively calm center of extremely low pressure known as the eye of the storm. Around the rim of the eye, winds may gust to more than 200 mph. The eye of a storm is usually 20 to 30 miles wide and may extend over 400 miles. The entire storm can be up to 340 miles in diameter, dominating the ocean surface and lower atmosphere for thousands of square miles.
Q. How Does a Hurricane Form?
A. Hurricanes only form over warm waters in the tropics (usually above 27°C, or about 81°F). Think of a hurricane like a giant engine. Its fuel is warm, moist air—which rises from from the oceans causing an area of lower pressure below. Then the air from surrounding areas with higher air pressure pushes in to the low pressure area. Then that “new” air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and cools off, the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the surface. Around their core, winds grow with great velocity, generating violent seas. Moving ashore, they sweep the ocean inward while spawning tornadoes and producing torrential rain and floods.
Storms that form north of the equator spin counterclockwise. Storms south of the equator spin clockwise. This difference is because of Earth’s rotation on its axis.
Q. How Do We Know a Hurricane Is Coming?
A. Now, thanks to satellite technology, no hurricane goes unnoticed. See our article on “Predicting Hurricanes: The Eyes Have It” to learn more.
It also usually takes several days to a week for a tropical storm to grow into a hurricane and there is often plenty of time to take precautionary measures unlike some extreme weather events (such as a tornado).
But if conditions are just right, a powerful major hurricane can develop in just hours. This has been called “rapid intensification” by the National Hurricane Center. When conditions are just perfect, a storm can increase its wind speed 35 mph in 24 hours or less—about two categories on the Saffir-Simpson scale, which grades hurricane strength from 1 to 5. Rapid intensification, however, is rare, with just one or two Atlantic storms per year undergoing such an acceleration.
Q. What Is the Cause of Hurricane Damage?
A. Hurricanes actually weaken when they hit land, because they are no longer being “fed” by the energy from the warm ocean waters. When hurricanes move over large landmasses, they can die out quickly because they lose the power of the heat and condensation. However, they often move far inland, dumping many inches of rain and causing lots of wind damage before they die out completely. So it’s not just high winds that cause danger; it’s the torrential rains and storm surges. A hurricane can last for 2 weeks or more over open water and can follow a path across the entire length of the eastern seaboard, coastal areas, and barrier islands.
Q. Which Areas Are Most Susceptible to Hurricanes?
A. All Atlantic and Gulf coastal areas are subject to hurricanes or tropical storms. Although rarely struck by hurricanes, parts of the Southwest and Pacific Coast suffer heavy rains and floods each year from the remnants of hurricanes spawned off Mexico. Islands such as Hawaii, Guam, American Samoa, and Puerto Rico also are subject to hurricanes.
Hurricane Felix (2007)
Q. Is a Hurricane the Same as a Cyclone? How Is Tropical Weather Classified?
A. A hurricane is actually one of three kinds of tropical storms, or cyclones, that circulate over tropical waters. The circulation is counterclockwise in the Northern Hemisphere. Tropical cyclones are classified as follows:
Tropical depression: An organized system of clouds and thunderstorms with a defined circulation and maximum sustained winds of 38 mph (33 knots) or less.
Tropical storm: An organized system of strong thunderstorms with a defined circulation and maximum sustained winds of 39 to 73 mph (34 to 63 knots).
Hurricane: An intense tropical weather system with a well-defined circulation and maximum sustained winds of 74 mph (64 knots) or higher. In the western Pacific, hurricanes are called typhoons. Similar storms in the Indian Ocean are called cyclones. Hurricanes are further classified by rank according to how strong their winds are.
Q. How Are Hurricanes Classified and What Are Hurricane Categories?
A. The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane’s present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region. Wind speeds are measured using a 1-minute average. See more about the Saffir-Simpson Hurricane Scale.
|Saffir-Simpson||Wind (mph)||Hurricane Examples|
|Category One||74 - 95||Allison (1995), Danny (1997)|
|Category Two||96 - 110||Bonnie (1998), George (1998), Gustav (2002)|
|Category Three||111 - 130||Roxane (1995), Fran (1996), Rita (2005)|
|Category Four||131 - 155||Opal (1995), Iniki (1992), Charley (2004), Katrina (2005)|
|Category Five||156 +||Andrew (1992), Matthew (2016), Irma (2017), Maria (2017)|
Q. What Do Hurricane Warnings Mean?
A. A hurricane watch means that hurricane-force winds are possible within 48 hours. A hurricane warning means that hurricane-force winds are likely within 36 hours.
Have you ever experienced a hurricane first hand? Tell us about it in the comments below.