As April draws to a close, we approach the beginning of the 2021 Atlantic Hurricane Season. After the devastation of the record-breaking 2020 season, many are looking to get prepared for this year. This year’s early predictions and forecasts are in, and we are expected to have an above-average season.
There are also some changes being made this year by the World Meteorological Association (WMO) and the National Hurricane Center (NHC).
2021 Hurricane Season Prediction
Researchers and forecasters from Colorado State University (CSU) and North Carolina State University (NCSU) have recently released their predictions of how active the 2021 hurricane season will be. While not identical, both forecasts predict an above-average season, with more named storms and hurricanes than the newly updated average (details on that update later). However, NCSU predicts a below-average to average number of major hurricanes, while CSU predicts a slightly above-average number of major hurricanes. Below is a table showing the predicted numbers against the new average. (Note: CSU gives single numbers, while NCSU gives a small range of numbers.)
Some changes for the 2021 hurricane season
The 2021 Atlantic Hurricane Season marks the beginning of a new decade, as well as some changes for the National Hurricane Center (NHC) and its reporting tools.
There is a new average
Because we have started a new decade, the 3-decade period used to calculate an average hurricane season has changed from 1981-2010 to 1991-2020. With this change, the averages used over the next 10 years have also changed. See the chart below to see the new averages.
Routine Tropical Advisories will start May 15th
2020 marked the 6th year in a row that a named storm was produced before the official beginning of hurricane season. Earlier this year, the World Meteorological Organization (WMO) considered moving the official start date to May 15th, 2 weeks earlier than the current June 1st start date.
While this change was not made, it was decided that starting this year, the National Hurricane Center (NHC) will begin providing routine Atlantic Tropical Weather Outlooks on May 15th every year. This advisory, issued 4 times a day, “…describes significant areas of disturbed weather and their potential for tropical cyclone formation during the next five days.” (NHC) This change will not affect the issuance of Special Tropical Weather Outlooks, issued outside of May 15th– November 30th when a weather disturbance shows any potential for tropical cyclone formation.
Supplemental List of Names
It was also decided by the WMO this year that the Greek Alphabet will no longer be used as the supplemental name list once the pre-determined list for the current season has been exhausted. The supplemental list will not be rotated like the standard list, but just like the standard list names can be retired and replaced if a storm creates devastating effects. 3 names were retired after the 2020 season, including 2 names from the Greek Alphabet list (Laura, Eta, and Iota).
The Greek Alphabet has only been used twice in an Atlantic Hurricane Season for supplemental names (2005 and 2020), but 2020 marks the first time a Greek Alphabet name was retired.
With the start of the 2021 Atlantic Hurricane season just a few weeks away, now is the ideal time to begin your hurricane season preparations. Some useful information about how to prep your home for hurricane season can be found here.
