At the time of publication, more than 12.3 million confirmed cases of COVID-19 had spread across 214 countries and territories, causing some estimated 30+ million job losses in the United States alone, and creating fears of a significant and prolonged global recession. When the novel coronavirus was officially announced by China in late January, few expected such a staggering worldwide impact – not only on the global economy – but also on society as a whole. It is within this dire context that U.S. organizations fix their gaze on preparing for the 2020 Atlantic Basin Hurricane Season.
The following sections offer a broad and high-level overview of 2020 hurricane forecasting. While the far-reaching and myriad impacts of COVID-19 are still being felt and mitigated across the business landscape, they will undoubtedly have a significant effect on long-standing strategies for planning and responding to tropical storms. As such, this document should be used as a guidepost for planning; organizations will need to consider planning and response strategies within the framework of COVID-19 and its impact on operations and workforce.
Effective hurricane preparation and claim planning can help an organization become more resilient and maintain critical operations, resume them more quickly after a loss, and manage a complex claim.
Brief Review of 2019 Hurricane Season
In 2019, economic and insured losses derived from natural catastrophes in the U.S. were substantially reduced from high-cost years in 2017 and 2018. The overall economic total was an estimated USD68 billion, of which USD36 billion was covered by public and private insurers. When compared to annual data from 2000-2018, economic losses in 2019 were 15 percent below the average (USD79 billion), though 43 percent higher than the median (USD47 billion). Insured losses were 9 percent lower than average (USD40 billion) and 43 percent higher than the median (USD25 billion).
While the U.S. endured two hurricane landfalls – Barry (Louisiana) in July and Dorian (North Carolina) in September – the most noteworthy tropical cyclone was Tropical Storm Imelda. That storm came ashore near Freeport, Texas in mid-September and produced prolific rainfall. Imelda became the fifth-wettest tropical cyclone on record in the Lower 48, and the fourth-wettest tropical cyclone in the state of Texas. Flooding from the system caused impacts in many areas previously damaged by Hurricane Harvey in 2017. Total economic damage was minimally estimated at USD3.5 billion.1
2020 Tropical Storm Forecasts
As of the Aon Impact Forecasting updates issued in June, Colorado State University (CSU) and Tropical Storm Risk (TSR) forecasts are listed below. CSU is projecting 19 named storms, 9 hurricanes, and 4 major hurricanes (Category 3+) whereas TSR is also projecting 17 named storms, 8 hurricanes and yet 3 major hurricanes (Category 3+).
Colorado State University
CSU has issued its June forecast for the 2020 Atlantic Hurricane Season. The forecast calls for 19 named storms, 9 hurricanes, and 4 major hurricanes (Category 3+) between the months of June and November.
The report cites several factors as to how and why this activity was forecast. The biggest reason surrounds the expectation that the current warm neutral El Niño-Southern Oscillation (ENSO) conditions are likely to transition to cool neutral ENSO or weak La Niña conditions by later this summer into the fall. The most recent statistical and dynamical ENSO model output shows a wide spread in possible scenarios during the peak months from August to October, though most do indicate varying levels of anomalous cooling during this time.
A second factor revolves around current sea surface temperatures across the North Atlantic Ocean. The Tropical Atlantic, Caribbean Sea, and waters along the U.S. East Coast are anomalously warmer than normal at present, though water temperatures are much cooler than normal in the far North Atlantic. CSU notes that while such cool conditions in the far North Atlantic are characteristic of a negative phase of the Atlantic Multi-decadal Oscillation (AMO), anomalous warmth elsewhere in the Atlantic does not equally suggest it. It is very important to note that there is considerable uncertainty in the current AMO phase and the expectation of what Atlantic sea surface temperatures will look like during the peak months of the hurricane season (August, September, October).
Tropical Storm Risk
Tropical Storm Risk (TSR) is forecasting 17 named storms, 8 hurricanes and 3 major hurricanes (Category 3+) between the months of June and November. This is slightly higher than TSR’s initial projection of tropical activity released in December 2019. The projected activity is expected to be 25 percent above the long-range norm since 1950, and 5 to 10 percent above the recent 2010-2019 (10-year) norm.
The agency cites that the main predictor for this forecast is the projected warmer than normal sea surface temperatures in the tropical North Atlantic Ocean and an arrival of neutral-to-weak La Niña ENSO conditions by the peak hurricane season months of August and September.
These expected ENSO conditions have resulted in a lowering of trade winds throughout the Atlantic’s Main Development Region (MDR) – including the Caribbean Sea and tropical North Atlantic – that typically leads to more cyclonic vorticity (spin) and decreased vertical wind shear. Each of these parameters should allow for more favorable atmospheric and oceanic conditions that lead to above-average cyclogenesis during the 2020 season.
The group stresses that the precision of hurricane season outlooks in April is often low and forecast uncertainties are amplified due to the unknown status of ENSO and atmospheric/ oceanic conditions in the Atlantic in a few months’ time. Forecast skill increases as the start of the season approaches.
For more details on what to consider when planning for the Atlantic Basin Hurricane season, check out What to Consider When Planning for Hurricanes.
Access Aon’s 2020 Atlantic Hurricane Season - Template & Checklists report for key elements of an enterprise-wide response and recovery process, including specific measures to address the potential impact of COVID-19.
1 Weather, Climate & Catastrophe Insight, 2019 Annual Report Aon Impact Forecasting