NOAA adjusts 2021 hurricane forecast, projects ‘above normal’ season

by | Aug 4, 2021

 

The National Oceanic and Atmospheric Administration (NOAA) updated its 2021 Atlantic Hurricane Season forecast, noting that the atmospheric and oceanic conditions remain conducive for an above-average hurricane season

In the latest outlook released on Wednesday, NOAA scientists predict that the likelihood of an above-normal hurricane season sits at 65 percent. Additionally, there is a 25 percent chance of a near-normal season and a 10 percent chance of a below-normal season. The adjusted forecast also shows that the number of expected named storms (winds of 39 mph or greater) is 15-21, including 7-10 hurricanes (winds of 74 mph or greater), of which 3-5 could become major hurricanes (Category 3, 4, or 5 with winds 111 mph or greater). This update includes the 5 named storms that have formed so far, with Hurricane Elsa becoming the earliest 5th named storm on record.

“After a record-setting start, the 2021 Atlantic hurricane season does not show any signs of relenting as it enters the peak months ahead,” said Rick Spinrad, Ph.D., NOAA administrator. “NOAA will continue to provide the science and services that are foundational to keeping communities prepared for any threatening storm.”

The report also showed that the Atlantic sea surface temperatures are not expected to be as warm as they were during the record-breaking 2020 season; however, reduced vertical wind shear and an enhanced west Africa monsoon all contribute to the current conditions that can increase seasonal hurricane activity. NOAA says these conditions are set against the backdrop of the ongoing warm phase of the Atlantic Multi-Decadal Oscillation, which has been favoring more active hurricane seasons since 1995.

“A mix of competing oceanic and atmospheric conditions generally favor above-average activity for the remainder of the Atlantic hurricane season, including the potential return of La Nina in the months ahead,” said Matthew Rosencrans, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center.

Following the new prediction, NOAA and others urged people to stock up and prepare for future storms.

“Now is the time for families and communities to ensure their preparations are in place,” said National Weather Service Director Louis W. Uccellini, Ph.D. “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.”

NOAA’s update to the 2021 outlook covers the entire six-month hurricane season, which ends Nov. 30. Throughout the hurricane season, NOAA’s National Hurricane Center (NHC) provides the hurricane track and intensity forecasts that emergency managers and communities rely on across areas at risk during a landfalling storm. NHC is the source for all watches and warnings for tropical storms, hurricanes, and related storm surge. The seasonal outlook from NOAA is not a landfall forecast as landfalls are typically only predictable within about a week of a storm potentially reaching a coastline.

The 2021 hurricane season commenced in May with tropical storm Ana. Between June and July, tropical storm Bill, tropical Storm Claudette, tropical storm Danny and hurricane Elsa formed. No named storms have appeared since Elsa.

Colorado State University is expected to release its updated hurricane season outlook on Aug. 5.

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