New Now you can listen to the articles in the Insurance Journal!
As the North Atlantic hurricane season officially begins today, forecasters continue to predict above-average storm activity.
Updating pre-season forecasts for North Atlantic hurricane activity continues to show 18 named storms, eight hurricanes and four major hurricanes (category 3 and above), according to Tropical Storm Risk (TSR).
“The last six hurricane seasons have been above average and this trend is expected to continue in the 2022 Atlantic hurricane season,” Allianz Global Corporate & Specialty (GATS) said in its annual hurricane season outlook.
The 2022 hurricane season is expected to be above the 1991-2020 average, with 14-21 tropical storms and six to 10 hurricanes, including three to six major hurricanes, the GATS said, noting that an above-average season would be seven to nine storms. reaching the strength of hurricanes and two to four becoming major hurricanes, which is Category 3 or higher.
Meteorologists predict the seventh season of hurricanes directly above normal
The 2021 Atlantic hurricane season saw a total of 21 named storms, of which seven were hurricanes (four reached major hurricane status), with the number of named storms exceeding an average of 14 and the total number of major hurricanes. also slightly above average. out of three, said GATS.
On average, the North Atlantic sees 14 named storms, 7 hurricanes and 3 major hurricanes, the RMS disaster modeling firm said.
Increased risk later in the season
Although uncertainties remain, TSR predicted that the 2022 hurricane season will be slightly less active than the previous two years, “but may pose an increased risk in the latter part of the storm season.” TSR is operated by EuroTempest, a London-based meteorological risk management service provider for the insurance, banking / finance, energy, construction and maritime industries.
TSR points out that some Niño forecasts predict a slight strengthening of La Niña’s current conditions until the autumn, which would increase the chance of increased activity at the end of the season.
The main factors that contributed to the above-average hurricane season in 2021 - the third busiest season on record - included La Niña, above-normal sea surface temperatures (SST) at the start of the season and above-average West African monsoon rainfall, he said. GATS, citing the National Oceanic and Atmospheric Administration (NOAA).
The GATS said everyone expects these factors to be replicated this year because:
- NOAA models show a 50% chance that La Niña conditions will persist during the peak of the Atlantic hurricane season.
- While tropical SSTs are now almost slightly below normal, they are well above normal in the Caribbean and subtropical North Atlantic, which correlates relatively well with what is commonly seen in the active seasons of Atlantic hurricanes. .
- An improved West African monsoon supports stronger waves in East Africa, which in turn generates many of the strongest and longest-lived hurricanes, according to the GATS, citing NOAA.
Favorable conditions for storm formation
Forecasts of an above-average hurricane season “reflect the state of the two major oceanic and climatic factors that historically dictate hurricane activity in the basin: El Niño Southern Oscillation (ENSO) and sea surface temperatures in the equatorial North Atlantic. It is estimated that ENSO will remain in a La Niña phase until the summer “, according to James Cosgrove, senior model at RMS, in an e-mailed statement.
“Such conditions reduce the vertical shear of the wind across the North Atlantic, which usually improves hurricane activity, providing a more favorable atmosphere for the development and intensification of storms,” he said. “In addition, sea surface temperatures in the tropical North Atlantic are expected to remain above average throughout the summer, which usually increases hurricane activity in the basin.”
Long-term statistics indicate that the likelihood of a hurricane reaching land in the United States increases during the busier seasons, but there are exceptions, Cosgrove said.
For example, 2010 was a very active year, but only a tropical storm hit the United States. “On the contrary, Hurricane Andrew, one of the most intense and costly hurricanes in U.S. history, was one of seven storms that developed during the quiet season of 1992. All that is needed is a storm approaching the earth to to make the season a memorable one, “he added.
Longer hurricane moments
While the North Atlantic hurricane season lasts six months from June 1 to November 30, the GATS said, recent hurricane seasons in the Atlantic have seen the first tropical storms formed before the official June 1 start date. considered moving the start date to May 15th.
The expansion of hurricane activity could be attributed to the development of advanced observation technologies, which can identify the weakest storms that never come close to any land mass, adding to the number of tropical storms, the GATS said.
However, this expansion of seasonal storm activity is more likely to be caused by higher sea surface temperatures, said Bastian Manz, senior climate risk analyst at Allianz Re.
“Tropical storms can only be formed and maintained for longer periods when the ocean temperature exceeds 27 ° C [80.6°F]”he added.
“Man-made global warming has increased the temperature of the atmosphere by 1.1 ° C since 1880, most of the excess net heat stored in the world’s oceans, including the North Atlantic. This has increased the duration of hurricane-sustaining SSTs, as well as the geographical spread of where they could occur. “
Manz acknowledged that there was no clear scientific consensus on whether climate change would increase the frequency of tropical storms. “However, there is more certainty that high-intensity storms will become more frequent, indicating the potential for greater damage.”
He said hurricanes are becoming increasingly difficult to predict as a result of the “rapid intensification” phenomenon, in which a storm intensifies significantly in a short period of time. “Hurricane Ida wind speeds [in 2021] it increased by 55 mph in the 24 hours before landing in Louisiana, “Manz confirmed.
“Scientists believe that climate change will make hurricanes wetter, increasing the risk of secondary hazards, such as floods and storm surges,” he added.
Today’s hurricanes cause 11% more precipitation than in a pre-industrial climate, Manz said, citing a study from The nature.
“This is exacerbated by hurricanes that slow down in their forward motion, so that precipitation accumulates in individual locations and causes extensive flooding,” he said, citing the example of Hurricane Harvey, which caused devastating floods after it crashed over Houston in 2017. Manz said the investigation indicated that Harvey’s “unprecedented rain” had been donedue to climate change.
Photo: Photo of the damage in New Orleans caused by Hurricane Ida. Photo credit: Bigstock
Hurricane Natural Disaster Disaster