Atlantic Hurricane Forecast Updates

Tropical storm activity across the Atlantic basin remains subdued, primarily due to persistent high wind shear over the Caribbean and the presence of dry, dusty air over the eastern Atlantic. While near-coastal development – similar to Tropical Storm Chantal earlier this month – remains a possibility in the short term, the broader risk of significant storm activity is expected to remain low through July.

Revised seasonal outlooks from both Tropical Storm Risk (TSR) and Colorado State University (CSU), issued earlier this week, have lowered their forecasts for the 2025 season. TSR attributed its revision to emerging climate signals that may contribute to a more stable atmosphere over the Atlantic during the peak months, reducing the likelihood of intense storm formation compared to earlier projections.

Although these reduced forecasts are generally favourable for Insurance-Linked Securities (ILS) investors, it is important to recognise the historical volatility of pre-season outlooks. Between 1995 and 2024, CSU’s forecasts for Accumulated Cyclone Energy (ACE) have shown an average change of 25% between April and August, with historical swings exceeding +80% and -50%. The moderate downward adjustments for 2025 reflect strong alignment among forecasting agencies and a consensus outlook that is broadly consistent with long-term averages (1995–2024), and slightly below the more active recent period (2016–2024).

Twelve Securis will continue to monitor both public forecasts and proprietary insights from research partners and will keep clients informed accordingly.