Tropical Storm Risk (TSR) has updated its forecast for activity levels through the 2024 Atlantic hurricane season, with a slight reduction within the numbers of storms and hurricanes expected to form, but still expecting 4 Category 1 or stronger hurricane landfalls in the US.
All the updated figures include activity seen to this point this season as much as Debby, so the explanation for the pull-back appears to be on account of the quantity of season already passed, fairly than any reduced conviction on the potential for more storms and hurricanes to form.
In its last update, around mid-July, the Tropical Storm Risk (TSR) forecast team called for 26 named tropical storms, 13 hurricanes and 6 major hurricanes, with seasonal ACE of 240.
Now, in today’s August update, the group is looking for twenty-four named tropical storms, 12 hurricanes and 6 major hurricanes to form, while the amassed cyclone energy (ACE) index forecast has been lowered to 230.
As ever, for the insurance, reinsurance, catastrophe bond and insurance-linked securities (ILS) industry, it’s the landfalling storms being in areas of high exposure concentration that basically matter.
While the numbers have dropped barely, it shouldn’t be read as a discount in risk, merely that point has passed and in what season is left there remains to be forecast to be a really high level of activity.
TSR said, “The TSR (Tropical Storm Risk) August forecast update for North Atlantic hurricane activity in 2024 continues to anticipate a hyper-active season.
“There continues to be very high oceanic heat content across the tropical North Atlantic and Caribbean Sea waters, combined with cold-neutral or weak La Niña conditions that are expected to develop and persist through August-October 2024.
“These two aspects are each expected to have a robust enhancing influence on the upcoming Atlantic hurricane season, although some uncertainties remain.”
The group also said it sees “a small likelihood the basin ACE index may very well be record breaking” this hurricane season.
They continued to say, “The explanation why the TSR August forecast for the 2024 Atlantic hurricane activity calls for a hyper-active season is our expectation that the very warm sea surface temperature anomalies currently present within the Atlantic Primary Development Region (MDR) and Caribbean Sea will persist through August-September 2024, cold-neutral or weak La Nina event will develop and persist through the remaining of summer and autumn. The unprecedented development of a category 4 hurricane in June east of the Windward Islands also implies a really lively season to come back.
“Although some uncertainties remain and a much less lively season than predicted here can’t be ruled out, the almost certainly consequence based on predictable climate aspects and analogue years is for the 2024 North Atlantic hurricane season to be well above the 1991-2020 30-year climatology when it comes to total basin and U.S. landfalling activity.”
The forecast stays well-above all climate averages and suggests a really busy Atlantic season through the approaching few months, but in addition show how seasonal forecasting needs to be adaptive to conditions and ought to be considered directional, fairly than accurate predictions for a way many hurricanes will actually occur.
On landfall risk for the US, TSR still forecasts 7 tropical storms and 4 hurricanes to hit the country over the course of this season.
Incorporating the most recent updated TSR forecast figures, alongside those others we track, makes no change to our Artemis Average forecast for the 2024 hurricane season, of 23 named storms, 12 hurricanes and 5 major hurricanes.
Track the 2024 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as recent information emerges.