Tropical Storm Risk (TSR) has increased its forecast for the 2021 Atlantic hurricane season in its latest update, with the team now predicting 9 Atlantic hurricanes, 4 of which are forecast to be major Category 3 or greater.
At the same time, the TSR forecast team now predicts activity levels that are 30% to 35% above the long-term norm and slightly above the 2011- 2020 10-year norm level, up from 25% to 30% above the long-term in their last forecast update from April.
It’s the latest reminder for the insurance, reinsurance and insurance-linked securities (ILS) industry that the official hurricane season is almost upon us and another active season is anticipated by meteorologists.
In fact, the TSR team gives a 59% chance that accumulated cyclone energy (ACE), a measure of tropical activity, will be above-average and a 42% chance that the 2021 hurricane season could be hyperactive,
At that April update, the TSR forecast team was calling for 17 named tropical storms, 8 hurricanes and 3 major hurricanes of Category 3 strength or greater, along with accumulated cyclone energy (ACE) of 134.
Now, the updated pre-season forecast calls for 18 named tropical storms, 9 hurricanes and 4 major hurricanes, with ACE of 140.
The team explains that there are now, “Updated climate signals that point to environmental fields in August-September 2021 being slightly more favourable for Atlantic hurricane activity than thought previously.
“This updated information comprises the April-May-June 2021 North Atlantic Oscillation being moderately negative which should lead to warming of tropical North Atlantic waters, and to the El Niño Southern Oscillation in August-September-October anticipated to be slightly negative which should contribute to reduced trade winds over the tropical North Atlantic and Caribbean Sea.”
This updated environmental factors should “enhance North Atlantic hurricane activity in 2021” the forecasters believe.
The forecast also includes some predictions for US landfalling storms, which are now pegged as likely to be 5 named tropical storms and 2 hurricanes, an increase of 1 tropical storm since the April update.
Hurricane forecasting remains an imprecise science of course, you only have to compare forecasts to the outcomes on previous years to see that.
But directionally, another forecast for a particularly active hurricane season should serve as a reminder for reinsurance market participants, as well as the ILS and catastrophe bond investment community, that there is always a very real threat of losses as the season progresses (remembering that it only takes one landfall to create significant human and financial impacts).
The full forecast from TSR can be found here.
Adding the latest TSR forecast update for the 2021 hurricane season to the data already aggregated from other main forecast teams tracked by the reinsurance and ILS industry, our Artemis average sits at 17 named storms, 8 hurricanes and 4 major hurricanes, with ACE of 144.
Track the 2021 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as new forecasts and information emerges.