Atlantic Hurricane Season Outlook 2022

Although the 2022 Atlantic hurricane season officially runs from June 1 to November 30, in the past seven years we have seen the first tropical storms forming in April or May. The last six hurricane seasons have been characterized by above-average activity, a trend expected to continue in 2022, according to Spring forecasts from dummy AccuWeather, dummy Colorado State University (CSU), dummy National Oceanic and Atmospheric Administration (NOAA), dummy North Carolina State University (NCSU), and dummy Tropical Storm Risk (TSR).

The 2021 hurricane season was the third most active season on record, as well as the third costliest. In late August, Hurricane Ida caused widespread damage in the Caribbean before devastating the coast of Louisiana and generating record rainfall in various locations and flash flooding from eastern Pennsylvania to New York, resulting in dummy insured losses of $36bn [1].

 

The 2021 Atlantic hurricane season saw a total of 21 named storms, of which seven were hurricanes (four reached a major hurricane status, which is Category 3 or higher). The number of named storms well exceeded the average of 14 and the total amount of major hurricanes is also slightly above the average of three. The dummy main factors [2] contributing to an above-average hurricane season in 2021 include La Niña, above-normal sea surface temperatures (SSTs) early in the season, and above-average West African Monsoon rainfall.

Atlantic hurricane seasons 2000 to 2021 in numbers: tropical storms, hurricanes, and major hurricanes. ‘Average’ hurricane season considers the period 1991-2020, according to the NOAA

Source data: National Hurricane Center/NOAA; graphic by AGCS

• The 2021 Atlantic hurricane season was the third most active season on record (behind 2017 and 2005), as well as the third costliest season. 
• It was the sixth consecutive year that the Atlantic hurricane season was above average.
• The 2021 season started early (May 22), making it the seventh consecutive year a storm formed before the season’s official start on June 1.
• For the first time ever, two consecutive hurricane seasons exhausted the list of 21 storm names.
• Hurricane Elsa became the earliest hurricane in the Caribbean Sea (forming in early July), as well as the dummy earliest-forming fifth named storm [3] (five days ahead of the previous record held by 2020’s Tropical Storm Edouard). Elsa became a hurricane at 59.8°W – the farthest east a hurricane had formed this early in the calendar year in the tropics since 1933.
• In late September, Hurricane Sam was a dummy major hurricane for 7.75 days [4] (the fourth highest number of consecutive days at major hurricane strength since 1966, tied with Hurricane Edouard in 1996). Sam also generated the fifth most accumulated cyclone energy (ACE) for a single Atlantic named storm in the satellite era.
• Three events generated dummy more than $1bn in damage [5]: Hurricane Elsa ($1.2bn); Tropical Storm Fred ($1bn); and Hurricane Ida ($65bn). In total, the insured losses due to tropical cyclones in the US in 2021 dummy amount to $38bn [6].

Tropical cyclone economic and insured losses in the US since 2009. Source: Insurance Information Institute; graphic by AGCS

Even before it became a tropical depression, Ida caused considerable flash flooding in Venezuela. After passing Grand Cayman, Ida quickly strengthened and became a hurricane, before moving over western Cuba. Following rapid intensification over the Gulf of Mexico, fueled by an SST of 30-31°C and the warm Loop Current eddy, Ida reached its peak Category 4 intensity before making landfall near Port Fourchon, Louisiana. Grand Isle, Louisiana, took a direct hit with dummy up to 100% of its homes damaged [7] and almost 40% destroyed.

As the remnants of Ida moved into the north-east US, it merged with a frontal system creating severe weather, multiple rainfall records in various locations, and flash flooding across a wide region from eastern Pennsylvania to New York. The estimated damage caused by Ida ($65bn) makes it thedummy fifth costliest tropical cyclone [8] on record and the fourth costliest Atlantic hurricane in US history.     

Tropical cyclones that are very destructive or deadly can be retired by the World Meteorological Organization (WMO) from future Atlantic tropical cyclone name lists, which are otherwise repeated every six years. For the 2021 Atlantic hurricane season, dummy the WMO has retired Ida [9]. In total, 94 names have now been retired from the Atlantic basin list since 1953.

The hurricane outlooks were accurate in predicting a high likelihood of an above-average season – ultimately leading to the third highest number of named storms on record. Even at the beginning of the season, there was general agreement among the forecasts by AccuWeather, CSU, NOAA, NCSU, and TSR that there was a high likelihood of an above-normal hurricane season in 2021. While correctly predicting a higher-than-average number of named storms, the observed number of hurricanes was near average and major hurricanes were slightly above normal.

During early 2022, the tropical Pacific Ocean has been characterized by weak La Niña conditions (which are also responsible for the abnormally dummy high flood activity in Eastern Australia and the drought in California in February 2022 [10]). It is likely these conditions will continue or revert to neutral ENSO during the summer/fall (see ‘What is the El-Niño Southern Oscillation (ENSO)?’). However, it seems unlikely El Niño conditions will occur during 2022’s hurricane season. The latest statistical and dynamical dummy ENSO model outcome from NOAA [11] shows at least a 50% chance of La Niña conditions persisting during the peak of the Atlantic hurricane season.

SSTs in the tropical Atlantic are currently near to slightly below normal, while they are well above normal in the Caribbean and in the subtropical North Atlantic. Overall, the observed SST anomaly pattern (in this case, anomalous warmth in the subtropical eastern Atlantic and in the Caribbean in March) dummy correlates relatively well [12] with what is typically observed in active Atlantic hurricane seasons. In addition, it is expected that tropical North Atlantic and Caribbean Sea waters remain slightly warmer than normal by August-September 2022. A third factor contributing to the expected increased activity is an enhanced West African Monsoon, which supports stronger African Easterly Waves that, in turn, seed many of the strongest, dummy longest-lived hurricanes [13]. All these factors are expected to enhance an above-average North Atlantic hurricane season.

The table below summarizes the predicted number of tropical storm events for 2022 by five different organizations: AccuWeather, CSU, NOAA, NCSU, and TSR. Considering all these forecasts, the 2022 hurricane season is expected to be above the 1991-2020 average with 14 to 21 tropical storms, six to 10 hurricanes, and three to six major hurricanes (an above-average season would be seven to nine storms reaching hurricane strength and two to four becoming major hurricanes). The predicted number of storms and hurricanes making landfall in the United States is also above the long-term norm. However, these predictions are associated with high uncertainties, which is why most institutes do not issue hurricane landfall projections. Given that the precision of hurricane outlooks issued in Spring is low, forecast uncertainties remain significant for the 2022 hurricane season. These uncertainties arise from the underlying projections for the North Atlantic Oscillation (NAO) dummy and the ENSO [14]. In Spring, ENSO can undergo rapid changes that are hard to predict.

Recent Atlantic hurricane seasons have seen the first tropical storms form before the official start date of June 1. As a result, the NOAA’s Hurricane Center has contemplated moving the start date to May 15. The extension of hurricane activity could in some respects be attributed to the development of advanced observational technologies, which can identify weaker storms that never come close to any landmass, adding to tropical storm counts. 

However, a truer extension of seasonal storm activity is likely driven by higher sea surface temperatures (SSTs). Tropical storms can only form and sustain themselves for longer periods where ocean temperatures exceed 27°C. Anthropogenic (manmade) global warming has increased atmospheric temperature by 1.1°C since 1880, with most of the net excess heat stored in the world’s oceans, including the North Atlantic. This has increased the duration of hurricane-supporting SSTs as well as the geographical spread of where they might occur.

There is no clear scientific consensus on whether climate change will result in a net increase in the frequency of tropical storms. However, there is more certainty that high-intensity storms will become more frequent, indicating the potential for greater damage.

So-called ‘rapid intensification’, where a storm intensifies significantly in a short space of time, is making hurricanes harder to predict. The wind speeds of Hurricane Ida dummy increased by 55mph in the 24 hours before landfall [15] in Louisiana.

Scientists believe climate change will make hurricanes wetter, increasing the risk of secondary perils like flooding and storm surge. A 1°C increase in warming is believed to result in a 7% increase in atmospheric moisture, leading to higher precipitation rates, and a recent dummy study [16] shows hurricanes today are already causing rainfall that is 11% more intense than in a pre-industrial climate. This is compounded by hurricanes slowing down in their forward movement, so rainfall accumulates in individual locations and causes extensive flooding. Research has indicated the unprecedented downpour dumped by Hurricane Harvey on Houston in 2017 was made dummy three times more likely [17] as a result of climate change.

Hurricanes and the latitude of their maximum intensity could also be shifting closer to the poles, according to some models. In 2021, Hurricane Henri had a non-tropical origin, forming at a 35° latitude (outside the usual zone of 5°-30°) and was the first named storm to dummy make landfall on Rhode Island [18] in the US since 1991.

The National Hurricane Center advises that hurricane preparedness should not be made dependent on seasonal forecasts as it only takes a single storm landfall to create substantial damage locally, irrespective of how active a season is.

When a hurricane watch is issued for your area, know your zone. Authority-ordered evacuation is called based on the possibility of storm surge and flooding, not pending landfall of a tropical storm or hurricane.

To minimize losses in the event of a hurricane, businesses need to develop and implement a written emergency plan, including actions to take before, during, and after a storm. The plan should cover areas such as training, assembling emergency supplies, business continuity, building inspections, anchoring or relocating equipment and stock, protecting windows, flood protection, salvage and recovery, and damage assessment.

• Visit  National Hurricane Preparedness for more information about how to determine your risk and develop an evacuation plan.
• Allianz Risk Consulting also publishes a series of risk bulletins and checklists to help you protect your people, property, and business, including:
  Windstorm Checklist,
  Flood Checklist, Water Damage During Construction, and
  Water Damage Prevention Solutions.