There is some divergence between forecasts for the 2018 Atlantic hurricane season, with some forecasters opting for above average levels of storm activity, while others like the Weather Company are opting for something closer to an average season.
The 2018 Atlantic hurricane season is now just over one month away, meaning forecasts are coming thick and fast with different meteorological opinions on just how much tropical storm and hurricane activity there will be this year.
It’s prudent to mention that the number of hurricanes and tropical storms that form in 2018 is in no way linked to the level of losses that insurance, reinsurance and ILS or catastrophe bond interests will suffer.
It takes just one landfalling storm for reinsurance contracts to face major financial impacts, so no matter what the forecast is the season could still prove to be costly, depending on where hurricanes track.
The Weather Company (a business owned by tech giant IBM) has released its prediction for the season, with an average forecast for 13 named tropical storms, 6 hurricanes and 2 major hurricanes of Category 3 or greater during the 2018 Atlantic season.
This is one of the lower forecasts from the list of meteorological organisations we track, but even with it added to the others, the Artemis average forecast for the 2018 Atlantic hurricane season remains 14 named storms, 7 hurricanes and 3 major hurricanes.
The Weather Company notes that Atlantic ocean temperature patterns are currently more aligned with average hurricane seasons, due to a cooler than normal patch in the eastern Atlantic and, to a lesser extent, in the central northern Atlantic.
In particular, should the ocean temperatures remain below normal in the eastern Atlantic it could result in less tropical development off the coast of Africa, a key hurricane breeding ground.
Additionally, the expectations is that ENSO conditions could move towards a more neutral level during the summer, which again suggests less hurricane and tropical activity, with a near average season the closest likeness to expected conditions.
The forecaster also notes an expected positive trend in the North Atlantic Oscillation (NAO), which can increase the pressure gradients around all-important Bermuda and Azores highs, which have a bearing on storm structure and steering.
A positive phase in the NAO could increase the chances of 2018 being a less active tropical year, according to the Weather Company.
The firm also notes the potential for Atlantic Multidecadal Oscillation (AMO) activity to move into a phase of lower activity, which again can be synonymous with hurricane seasons featuring less activity.
But with the correlation between storm or hurricane numbers and landfalls not strong, none of this means the U.S. will not experience a major landfalling hurricane this year.
Clearly, the lower the number of storms that form is, the lower the chances of multiple landfalls occurring. But it does only take one hurricane tracking towards a highly populated area of U.S. coastline for the reinsurance and ILS sector to face major losses.
Keep track of our 2018 Atlantic Hurricane Season page where we will update the forecast numbers over the coming months and then track every storm of the season.