‘Extremely Active’ Hurricane Season Possible for Atlantic Basin

NOAA urges preparedness as we enter peak months for hurricane development.

Atmospheric and oceanic conditions are primed to fuel storm development in the Atlantic, leading to what could be an “extremely active” season, according to forecasters with NOAA’s Climate Prediction Center, a division of the National Weather Service. Today, the agency released its annual August update to the Atlantic Hurricane Season Outlook, initially issued in May.

The 2020 Atlantic hurricane season has been off to a rapid pace with a record-setting nine named storms so far and has the potential to be one of the busiest on record. Historically, only two named storms form on average by early August, and the ninth named storm typically does not form until October 4. An average season produces 12 named storms, including six hurricanes of which three become major hurricanes (Category 3, 4, or 5).

This is one of the most active seasonal forecasts that NOAA has produced in its 22-year history of hurricane outlooks. NOAA will continue to provide the best possible science and service to communities across the Nation for the remainder of hurricane season to ensure public readiness and safety. We encourage all Americans to do their part by getting prepared, remaining vigilant, and being ready to take action when necessary.” 

—Wilbur Ross, U.S. Secretary of Commerce

The updated outlook calls for 19-25 named storms (winds of 39 mph or greater), of which 7-11 will become hurricanes (winds of 74 mph or greater), including 3-6 major hurricanes (winds of 111 mph or greater). This update covers the entire six-month hurricane season, which ends Nov. 30, and includes the nine named storms to date. 

The updated 2020 Atlantic hurricane season probability and numbers of named storms. (NOAA)

A comprehensive measure of the overall hurricane season activity is the Accumulated Cyclone Energy (ACE) index, which measures the combined intensity and duration of all named storms during the season. Based on the ACE projection, combined with the above-average numbers of named storms and hurricanes, the likelihood of an above-normal Atlantic hurricane season has increased to 85%, with only a 10% chance of a near-normal season and a 5% chance of a below-normal season.

“This year, we expect more, stronger, and longer-lived storms than average, and our predicted ACE range extends well above NOAA’s threshold for an extremely active season.”  

—Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center

Current oceanic and atmospheric conditions that make an “extremely active” hurricane season possible are warmer-than-average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, reduced vertical wind shear, weaker tropical Atlantic trade winds and an enhanced west African monsoon. These conditions are expected to continue for the next several months. A main climate factor behind these conditions is the ongoing warm phase of the Atlantic Multi-Decadal Oscillation, which reappeared in 1995 and has been favoring more active hurricane seasons since that time. 

Another contributing climate factor this year is the possibility of La Nina developing in the months ahead. Indicative of cooler-than-average sea surface temperatures in the equatorial regions of the eastern Pacific Ocean, La Nina can further weaken the wind shear over the Atlantic Basin, allowing storms to develop and intensify. 

The 2020 Atlantic tropical cyclone names selected by the World Meteorological Organization. (NOAA)

NOAA’s hurricane season outlook is for overall seasonal activity and is not a landfall forecast. Landfalls are largely determined by short-term weather patterns, which are only predictable within about a week of a storm potentially reaching a coastline. NOAA’s National Hurricane Center provides tropical weather outlooks out to five days in advance, provides track and intensity forecasts for individual storms, and issues watches and warnings for specific tropical storms, hurricanes and the associated storm surge.

NOAA has the most highly trained and dedicated forecasters that serve to protect American lives and property. With improved forecast skill, new storm surge products, and new observations, such as GPS Radio Occultation, we are better positioned than ever before to keep Americans out of harm’s way. It is now more important than ever to stay informed with our forecasts, have a preparedness plan, and heed guidance from local emergency management officials.”

—Neil Jacobs, Ph.D., acting NOAA administrator

This hurricane season FEMA encourages residents in hurricane-prone regions to keep COVID-19 in mind when making preparations and during evacuations. Visit https://www.ready.gov/hurricanes for more information. Stay tuned to the National Hurricane Center for the latest about tropical storm and hurricane activity in the Atlantic.

Media contact: Lauren Gaches, 202.740.8314

60% Chance of Above-Normal 2020 Atlantic Hurricane Season

The National Oceanic and Atmospheric Administration’s (NOAA)’s Climate Prediction Center is predicting a 60 percent chance that the 2020 Atlantic hurricane season will be above-normal. There is a 30 percent chance of a near-normal season and just a 10 percent chance of a below-normal season.

We can expect a likely range of 13-19 named storms, of which 6-10 are expected to become hurricanes. Of those hurricanes, 3-6 are expected to become major hurricanes of Category 3 or higher.

The Atlantic hurricane season runs from June 1 to November 30 and peaks from mid-August to late October.

NOAA is predicting ENSO neutral or La Niña conditions, along with warmer-than-average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea, coupled with reduced vertical wind shear, weaker tropical Atlantic trade winds, and an enhanced west African monsoon.

NOAA will upgrade the hurricane-specific Hurricane Weather Research and Forecast system (HWRF) and the Hurricanes in a Multi-scale Ocean coupled Non-hydrostatic model (HMON) models this summer. The National Hurricane Center provides up-to-date forecasts, data, and tools.

Carbon Dioxide at 411 ppm

Latest Measurement: February 2019

Carbon dioxide (CO2) is released through deforestation, burning fossil fuels and volcanic eruptions. It is important to track because it traps greenhouse gas. The above chart by NASA NOAA shows CO2 levels measured at Mauna Loa Observatory, Hawaii, in recent years, with average seasonal cycle removed.