April 20, 20211350Views
NOAA graphic reflecting 14 as the new annual storm average, replacing the former average 12

The National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Centre has updated average Atlantic Hurricane Season activity based on the data from the most recent 30-years of recorded activity, according to an April announcement.

Beginning with the 2021 hurricane season, averages are calculated based on activity from 1991-2020. Forecasters now expect the average hurricane season will bring 14 named storms and 7 hurricanes to the region. 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.

According to NOAA, the change may be attributed to improvements in observation technology such as NOAA’s environmental satellites and continued hurricane reconnaissance. The warming ocean and atmosphere, which are influenced by climate change, may also be factors. The update also reflects a very busy period over the last 30 years, which includes many years of a positive Atlantic Multi-decadal Oscillation, which can increase Atlantic hurricane activity.

“These updated averages better reflect our collective experience of the past 10 years, which included some very active hurricane seasons,” said Matt Rosencrans, NOAA seasonal hurricane forecaster. “NOAA scientists have evaluated the impacts of climate change on tropical cyclones and determined that it can influence storm intensity. Further research is needed to better understand and attribute the impacts of anthropogenic forcings and natural variability on tropical storm activity.”

NOAA’s initial seasonal outlook for the 2021 hurricane season will be released in late May. The Atlantic Hurricane Season is from June 1 through November 30.