2 June 2023Analysis

Acrisure Re predicts normal 2023 Atlantic hurricane season

Acrisure Re has published its 2023 Pre-Season Hurricane Outlook report which forecasts a close to normal hurricane season, albeit with higher uncertainty than in most years due to both favourable and unfavourable conditions.

After six years of above average activity in the Atlantic basin, 2022 saw near normal to slightly below normal activity, despite the pre-season forecasts for an above average season and a record positive Atlantic Multidecadal Oscillation (AMO) index in September. After three years of La Niña conditions in the Pacific, El Niño conditions are forecasted to return and potentially keep the Atlantic to a second near-normal season.

According to Acrisure Re it is possible that there will be more activity in the eastern and central Atlantic this year, where storms that form generally recurve out to sea, with below normal activity in the western Atlantic and Caribbean due to stronger wind shear expected.

Acrisure Re’s analytics team examined the following key variables to create a qualitative overview of the likely conditions this summer:

Forecasted Atlantic sea surface temperature (SST) is warmer than last year, especially in the Main Development Region (MDR). Nearly the entire Atlantic and Gulf of Mexico are forecasted to be above normal, suggesting more hurricane activity.

The El Niño Southern Oscillation (ENSO) is predicted to be in a moderate to strong El Nino phase, which could lead to strong vertical wind shear and suppressed hurricane activity.

Positive ENSO conditions are associated with a higher proportion of storms making landfall for Gulf clusters in Acrisure Re’s forecast model, despite lower frequency of storms.

Past analog years of 1978 and 1993 would indicate Quasi-Biennial Oscillation (QBO) is trending toward a negative anomaly but should remain positive for most of the season. Positive QBO values are often associated with more Cape Verde storms forming in the deep tropics.

Conditions in the Sahel region of Africa appear to be very close to average. This means dust is unlikely to play a major role in suppressing hurricane activity.

“After an extended period of above average hurricane season predictions, it is somewhat relieving to see the conditions swaying back toward normal,” said Simon Hedley, chief executive of Acrisure Re. “However, uncertainty is higher than normal and a below or above average Hurricane season is still a possibility. Our expert and experienced analytics team will continue to monitor the models to ensure our brokers advise clients accordingly on property coverage.”

Ming Li, global head of catastrophe modelling, Acrisure Re, said: “Our statistical and dynamic models, as well as our review of key variables, suggest a near average hurricane season for 2023. However, despite the forecast, the hurricane season can be defined by one storm. There is a level of uncertainty given the competing nature of the predicted Atlantic and Pacific SST conditions, the rate of development of El Niño and the recent lack of forecast verification for Atlantic SSTs.”