Very active, possibly impactful 2021 hurricane season forecast: WeatherBELL

Another forecaster we track has issued an early forecast for the 2021 Atlantic hurricane season, with WeatherBELL Analytics saying it anticipates another “very active season”, but with impacts potentially being seen further to the east and a warning about storms developing and intensifying closer into the US mainland.

As we explained yesterday, forecasts are now beginning to emerge and more are expected through the rest of this week, and it seems that we can expect forecasts to increase their numbers slightly from the very far out pre-season prognostications.

Yesterday we added the latest from forecaster Accuweather, who called for 16-20 named storms to form during the 2021 Atlantic tropical season, 7 to 10 of which would become hurricanes and with between 3 to 5 forecast to become major hurricanes (Category 3 or higher with maximum sustained winds of 111 mph or greater).

Now, WeatherBELL has forecast an even more active season, with 16 to 22 named tropical storms forecast to form, between 9 and 13 of which are forecast to reach hurricane status and with between 3 and 6 becoming major hurricanes.

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WeatherBELL also provides a forecast for Accumulated Cycle Energy (ACE) in the Atlantic basin during the 2021 hurricane season, forecasting a figure of between 150 and 200.

However, the forecaster also notes the chance of some storms forming far from land and accumulating ACE.

WeatherBELL believes that La Nina will continue to be a factor through the 2021 Atlantic hurricane season, saying they expect “some form of a La Niña or at least shadow of it.”

They point to the chances of the 2021 Atlantic hurricane season seeing impacts further to the east than last year’s season saw, saying “there is some weak correlation to storms moving farther to the east in second-year La Niñas.”

As well as the chances of storms moving towards the eastern seaboard, WeatherBELL also warns of the chances of in-close development during the 2021 season.

With a gut feeling that most of the hurricane season action will be seen between New Orleans and Cape Hatteras, “The specter of in-close development is rearing its ugly head.”

That is always something to watch out for in the insurance, reinsurance and insurance-linked securities (ILS) market, as storms that form closer into land, or intensify as they near land, are much harder to make accurate impact forecasts for.

That also makes portfolio management and hedging decisions more challenging to make, of particular relevance to reinsurance, catastrophe bond and ILS markets of course.

WeatherBELL also offers a forecast for major storm impacts, using a proprietary Power and Impact Scale.

For the 2021 Atlantic hurricane season, the forecast suggests between 3 and 6 hurricane landfalls will occur and that between 2 and 4 of these will be major impact landfalls.

WeatherBell looks at more than just wind speeds to define what could constitute a hurricane landfall that has major impact, with factors such as the extent of hurricane force winds, sea level pressure and reported wind speeds all important.

The forecaster points to Superstorm Sandy, saying that for a Category 1 storm there were clear signs its landfall would be more impactful than a simple Cat 1 designation would bely. Hence its Power and Impact Scale tries to take some of these factors into account to provide some insights on what to expect, in terms of the potential for damaging hurricanes during the coming 2021 Atlantic season.

After yesterday’s update on the Accuweather forecast our Artemis average sat at 16 named storms, 7.5 hurricanes and 3 major hurricanes, which is above the longer-term averages, but aligned with the average of recent seasons.

Now, including WeatherBELL’s forecast numbers, our Artemis average has risen to 17 named storm, 8 hurricanes and 3.5 major hurricanes, with ACE of 147.

We have to reiterate that no matter how many storms are forecast, it can take just one landfall of a hurricane in a highly populated and urbanised coastal area to cause billions in economic damages, along with significant losses that flow into reinsurance structures, meaning even the most benign hurricane forecasts can still result in impactful seasons.

Similarly, a forecast for a particularly active season can also result in relatively minor financial costs, should hurricanes form far out in the ocean and fail to reach land at any major strength.

As a result, it’s important to use forecasts wisely and to form your own views on the risk a particular season poses, but these forecasts from meteorologists are helpful in seeing what kind of trends may be expected.

With forecasts expected from Tropical Storm Risk and Colorado State Uni in the coming days, we’ll update you as those and others are added into our numbers as the hurricane season approaches.

Track the 2021 Atlantic tropical storm and hurricane season on our dedicated page and we’ll update you as new forecasts and information emerges.