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NOAA predicts another active Atlantic hurricane season in 2021

On Thursday (May 20, 2021) NOAA’s Climate Prediction Center released its annual hurricane season outlook. The agency predicts that the 2021 Atlantic hurricane season will be busier than average. However, the forecasters don’t anticipate the historic level of storm activity seen in 2020’s record-breaking season, which had 30 named storms and was only the second time the list of storm names was exhausted in a season since naming began in the 1950s.

Hurricane season officially starts June 1 and extends through November 30, although the National Hurricane Center reported May 22 that subtropical storm Ana – which formed overnight off the coast of Bermuda – had become the season’s first named storm, with maximum winds of 45 mph (72 kph). That makes 2021 the seventh straight year in which at least one named storm has developed in the Atlantic basin before hurricane season’s official start date. As of May 23, Ana has developed further into a tropical storm.

Subtropical storm Ana formed in the Atlantic Ocean early Saturday, May 22, 2021. Image via NOAA/ CBS News.

For the 2021 season ending on November 30, NOAA scientists predict a likely range of 13 to 20 named storms (winds of 39 mph or higher – about 63 kph). Six to 10 of these could become hurricanes (winds of 74 mph or higher – about 120 kph), including three to five major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher – about 180 kph).

How do forecasters make hurricane season predictions?

Pie chart of different kinds of tropical storms.
Estimated percentages of types of storms. Image via NOAA.

Last month, NOAA updated the statistics used to determine when hurricane seasons are above-, near-, or below-average relative to the latest climate record. Based on this update, an average hurricane season produces 14 named storms, of which seven become hurricanes, including three major hurricanes.

Poster showing average numbers for previous 30-year period on left and latest one on right.
This graphic captures the changes in Atlantic hurricane season averages from the last three-decade period of 1981-2010 to the most current such period, 1991-2020. The updated averages for the Atlantic hurricane season have increased with 14 named storms and 7 hurricanes. The average for major hurricanes remains unchanged at 3. The previous Atlantic storm averages, based on the period from 1981 to 2010, were 12 named storms, 6 hurricanes, and 3 major hurricanes. Learn more here. Image via NOAA.

Ben Friedman, acting NOAA administrator, said in a statement:

Although NOAA scientists don’t expect this season to be as busy as last year, it only takes one storm to devastate a community.

The forecasters at the National Hurricane Center are well-prepared with significant upgrades to our computer models, emerging observation techniques, and the expertise to deliver the life-saving forecasts that we all depend on during this, and every, hurricane season.

Bottom line: NOAA predicts that the 2021 Atlantic hurricane season will be busier than average.

Via NOAA

Posted 
May 22, 2021
 in 
Earth

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