Active Hurricane Seasons: The New Normal
Although Hurricane Henri was downgraded to a tropical storm and narrowly missed densely populated Long Island, New York, Kroll Bond Rating Agency (KBRA) notes the following as we approach the peak of hurricane season:
An increase in landfall events will continue and further challenge the risk management of property insurers.
Hurricane Henri, which made landfall as a tropical storm in Rhode Island, will be a relatively minor loss event for the industry. However, insurers who have increased their catastrophe retentions will have earnings declines and experience surplus erosion.
There will be significant uninsured losses for individual homeowners from storm surge and flooding.
The Winds of Change
The Colorado State University (CSU) Tropical Meteorology Project team—one of the pioneers of hurricane forecasting— updated on August 5 its Atlantic hurricane season forecast, which calls for the sixth consecutive year of above-average activity. In 2021, the Atlantic produced a pre-season storm for the seventh year in a row, following the formation of Tropical Storm Ana on May 22. In the same month, the National Oceanic and Atmospheric Administration (NOAA) released its latest 30-year average, which is re-established every 10 years. The average number of named storms, hurricanes, and major hurricanes have continued to increase (see Figure 1). The new 30-year average is over 40% higher for named storms and 60% higher for major hurricanes than the 30-year average from 1971 to 2000. Tropical cyclone activity over the last five years has witnessed a similar trend toward the “new normal.”
As KBRA previously noted, the 2020 Atlantic hurricane season saw a record-breaking 30 named storms, including 13 hurricanes and six major hurricanes. The number of named storms exhausted the 21 annual pre-designated list of names, with the last nine named storms designated with Greek letters. This was only the second time in history that the Greek alphabet was used; and it will also be the last. Following the 2020 season, the World Meteorology Organization (WMO) decided to discontinue the use of Greek alphabet names if the season’s list of names gets exhausted again. Going forward, they will use a list of 21 supplemental names developed by the WMO, which follows the existing English alphabetical naming convention, and suggests the WMO expects the need for more than 21 names in a hurricane season will be more typical than in the past.
As with 2020, named storms in 2021 are far outpacing the historical average (see Figure 2). While CSU’s latest forecast calls for 18 named storms (down from its previous forecast of 20), other forecasts range between 20 and 25. A scenario in which there are 20 named storms would rank 2021 in the top three active hurricane seasons of all time, following 2020 and 2005.
Climate Change and Increased Landfalls
KBRA also notes that while there are differing views within the scientific community as to whether climate change is helping to generate increased frequency of hurricanes, there is general consensus that climate change has contributed to greater storm severity. The Center for Climate and Energy Solutions (C2ES) states that “Although scientists are uncertain whether climate change will lead to an increase in the number of hurricanes, there is more confidence that warmer ocean temperatures and higher sea levels are expected to boost their intensity and impacts. Stronger hurricanes will be far more costly in terms of damages and deaths without action to make coastal (and inland) areas more resilient.” Of the 30 named storms in 2020, a record 12 made landfall in the U.S. This trend has continued into 2021, as five of the first eight named storms have made landfall in the U.S. (see Figure 3), and six named storms have made landfall in the Americas.
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