If you were busy this weekend, you might have been a bit surprised at the rapid development of Hurricane Beryl. You might also have completely missed the short-lived third storm of the season, tropical Storm Chris, that formed in the Bay of Campeche. On average, the third Atlantic named storm forms on August 3rd. In reality, the insurance industry should not be surprised as the forecast since early spring has been calling for a hyperactive season. Beryl quickly intensified into an intense Category 4 hurricane over the weekend, breaking several records. One of the most impressive is the earliest Category 4 Atlantic hurricane on record, beating Hurricane Dennis, which became a Category 4 hurricane on July 8, 2005. A truly unprecedented hurricane for the time of year.
Another interesting fact is that while Hurricane Beryl's winds were at Category 4 speeds, the central pressure did reflect quite the same intensity. Basin-wide, it was one of the higher central pressures observed in a Category 4, which was likely a result of two factors; a small compact circulation and unusually low latitude. What is impressive is that we can measure all these details at such a fine resolution and compare our hurricane records dating back to 1851. While there are records going back this far, the quality and completeness dropped off significantly prior to 1966, when continuous satellite monitoring became the standard, and globally, the coverage was inadequate until the early 1980s. Now, satellites provide extensive detail, including 1-minute updates from satellites and having aircraft in named storms almost constantly. In fact, just last week, SpaceX launched the next generation of satellite GOESU, which will only aid in higher data results and better hurricane records in the future.
Beryl’s Current Impacts
Hurricane Beryl slightly weakened overnight as it underwent an eye-replacement cyclone. It is unfortunate timing as the overall circulation will now become more extensive as it passes over the southern Windward Islands. It will now likely undergo another stage of strengthening as the overall atmosphere and oceanic remains very favourable for intensification as it heads into the Caribbean. The occurrence of a Category 5 is still a possibility. Of course, none of this should be a surprise as many updates, including these BMS Tropical Updates, since early spring have been pointing out that the primary fuel for these named storms is very warm Sea Surface Temperatures. In fact, these SSTs along Hurricane Beryl's track are running at record or near record levels for the week, with a deep reservoir of ocean fuel. Waters are as hot as they typically are in late August and September, no doubt a big player in Beryl's record June intensity.
Within the next several hours, based on the most recent forecast as outlined in our BMS iVision Verisk Respond forecast, the small islands between Grenada and St. Vincent and the Grenadines are going to take a direct hit, particularly the small island of Carriacou just north of Grenada. The wind speeds are off the scale, which is not good. These islands face the most extreme impact, including dangerous wind, rainfall, and storm surge. As mentioned, Hurricane Beryl is on the upswing after an eyewall replacement cycle and is once again a Category 4 hurricane. Unfortunately, it should continue to intensify as it closes in on Grenada, St. Vincent, and the Grenadines, which are bigger storms. This morning, tropical storm force winds were observed on Barbados, roughly 100 miles from the center of Hurricane Beryl.
Unfortunately, Beryl will have devastating impacts on all these islands. The insurance industry does not have to look too far back in recent memory for reference points. Storms such as Hurricane Maria (2017) & Hurricane Dorian (2019), help us understand what these small Island communities could be facing in the coming weeks and months. When Hurricane Maria struck the eastern Caribbean island of Dominica in 2017, the Category 5 hurricane damaged 98% of building roofs and caused US$1.2 billion (£950 million) in damage. Dominica effectively lost 226% of its GDP overnight. The return period for major hurricanes impacting these islands is about every 50 years or more. In fact, with an estimated impacted wind speed of 150 mph, this would be the strongest hurricane to impact the areas in the historical record. Although the overall GDP is around 2 billion dollars for Saint Vincent and Grenadines and Grenada, which likely means a small insured loss in the 100’s of millions, the overall economic impacts will be substantial for the months ahead.
Beryl’s Future Track
Although the immediate impact and concerns are on Windward Island for the insurance industry, it is hard not to focus on the long-range forecast for Beryl. Even with increased skill in the long-range forecasts, there is still a large amount of uncertainty as the potential impact in the Gulf depends partly on what happens with the upper-level ridge centered off the Carolinas and a trough entering the Midwest later this week. There is about a 10% chance of insurance industry impacts in Texas. Hence, the probability is not zero, and insurance carriers must pay attention to the mid-week forecast.
However, rest assured, the insurance industry will likely be exposed to some scary-looking forecast of Beryl making landfall somewhere along the Gulf Coast. Be careful, as there are often single deterministic runs of a weather model. While technically, these forecasts are possible, they are just one run, which gives the insurance industry no information about how likely this is to occur.
This is why, for a long-range hurricane forecast, the insurance industry should first focus on the NHC cone of uncertainty that looks at the next 5 days of possible outcomes. Anything beyond the five-day forecast the NHC provides, one should see if the forecast model is consistent over several days of a scenario. That is one way to build confidence in a possible future outcome of that model. The other useful forecasting tool is to use ensembles that help account for uncertainty in the atmosphere's initial state and model tendencies, providing a larger range of possible outcomes.
Now, even ensembles can be misleading, and Beryl provides an excellent example of that. When looking at the ensembles below, one often focuses on the ensemble mean, which is the average of all the tracks. At the end of a forecast period for Beryl, one might notice that the ensemble mean track jumps way north as it approaches day 10 because so many of the southern tracks terminate early across the Yucatan of Mexico. This leaves only the northern tracks left, which adjust the mean. Yet, what really might happen is Beryl could just dissipate over the Yucatan of Mexico.
As of right right now, it is too early to say what happened with Beryl. It seems there is about a 10% chance of insurance impacts to Texas, and the probability will increase or decrease later in the week as there is more serenity with how the upper air pattern over North America will evolve.
Behind Hurricane Beryl is another tropical wave labeled Invest 96L, but due to cold water upwelling, there is likely less support for development, and most models only show a weak-moderate tropical storm if one even develops. The good news is that the extended range into the middle of July appears to show that the Atlantic might lull in activity as the upper air pattern provides a less conducive environment for development.