A British website, TropicalStormRisk.com, which has won insurance industry awards for its accuracy, predicts that North Atlantic hurricane activity in 2024 will be more than 50% above the long-term average and 30% above the average for the last three decades.
The website claims it has the best performing statistical seasonal forecast model at all lead times for the period 2003-2023. But it confesses that forecasts six months in advance have high degrees of uncertainty, especially since it’s hard to predict summer sea surface temperatures in the Caribbean during the winter. That said…
By comparison, the 2023 Atlantic season produced 3 major hurricanes, 7 hurricanes and 10 tropical storms. The 2023 season ranked fourth for the most-named storms in a year since 1950. An average season has 14 named storms, seven hurricanes and three major hurricanes, according to NOAA.
Comparisons with Running Averages
Here’s how TSR’s predicted 2024 totals compare to 10-, 30-, and 74-year norms.
ACE stands for Accumulated Cyclone Energy. Various agencies use the metric to express the energy released by a tropical cyclone during its lifetime. The concept can also be applied to groups of cyclones, including a whole season’s worth.
When looking at ACE, TSR claims a greater than 50% chance that 2024 will be in the top third of all seasons between 1991 and 2020.
Methodology and Key Predictors for 2024
TSR divides the North Atlantic into three regions and forecasts each separately before summing them. The three regions include the Tropical North Atlantic, Caribbean Sea and Gulf of Mexico. Their model incorporates August through September sea surface temperatures and July through September trade wind speeds over the prior 10-year period.
The group believes El Niño has peaked and will weaken throughout the winter and spring of 2024. El Niño events generally suppress Atlantic hurricane activity, according to the National Weather Service. So a weakening El Niño would allow a resurgence of hurricane activity.
TSR also calls for ACE-activity above the 1991-2020 climate norm level based on predictions of warm sea surface temperatures in the Atlantic Main Development Region and Caribbean Sea during August-September 2024. However, they caution that a high degree of uncertainty exists six months out.
For the complete report, click here. Warning: you may need a PhD to understand the statistical reasoning behind their forecasts.
Posted by Bob Rehak on 1/17/24
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