The Atlantic hurricane season officially concludes at the end of November, and what may be its final chapter is now unfolding in the western Caribbean. It seems fitting that the intense 2024 Atlantic hurricane season might end on a dramatic note. Apparently, Hurricane Rafael did not make the cut, as it dissipated in the Central Gulf of Mexico on Sunday, November 10th. Now, a more dramatic ending that could possibly take shape could bring some late-season insurance industry losses.
Hyperactivity
By all accounts, the 2024 Atlantic season is now above average, and according to the metric Accumulated Cyclone Energy (ACE) index, the season is hyperactive. A hyperactive hurricane season is defined by an ACE index exceeding 159.6, and Hurricane Rafael has pushed this season’s ACE slightly above that threshold to 159.77. As of November 12th, all metrics for the 2024 Atlantic hurricane season remain above normal levels. More intense metrics for hurricanes, hurricane days, major hurricanes, and major hurricane days are above average than metrics for weaker storms, named storms, and named storm days.

This also means that very active seasonal forecasts are now starting to verify, which is impressive given the general lack of overall activity after Hurricane Beryl from the start of July to the end of August. With the potential for further storm development in the western Caribbean—where the next named storm would be Sara—the 2024 Atlantic hurricane season currently stands as the 11th extremely active season of the satellite era. Other seasons include: 1995, 1996, 1998, 1999, 2003, 2004, 2005, 2010, 2017, 2020. Of course, the seasonal forecast at the start of the season predicted that this would be an active season due to the following reasons:
- Ocean temperatures: The ocean was often 2°F warmer than average, which creates better conditions for tropical storms and hurricanes.
- Weak La Niña / Neutral: The La Niña climate pattern decreases atmospheric stability, which is better for storm development.
- Trade winds: Light trade winds allow hurricanes to grow in strength without disruption.
- The second half of the season provided two very active positive phases of the Madden-Julian Oscillation (MJO)
Unfortunately, as these conditions persist, more trouble is expected as late-season activity continues to be enhanced, which we will see evidence of this weekend.
Soon To Be Named Sara Forecast Complications
If you are still paying attention to the National Hurricane Center website, you will notice that over the last few days, they have been targeting areas of possible development in the Western Caribbean. The probability of development will now be up to 90% in the next two days.
This area of tropical trouble has been labelled invest 99L, which allows for the running of unique hurricane models and the addition of better observable capabilities, like special hurricane hunter flights. The first one is scheduled for this afternoon, and if the aircraft finds enough evidence of convection and a low-level center, it might get its official designation.
All indications suggest a system poised for rapid development, likely to be drawn northward and then catapulted northeastward ahead of a significant fall cold front and a winter weather system impacting the central plains late next week. Some models project that the potential storm Sara may pass over Central America before moving north, which could initially weaken it, making this system one to watch closely. However, if a potential storm Sara can track through the Yucatan Channel, it would maintain intensity in the southern Gulf of Mexico. Potential Sara could also get stuck in the Caribbean and never reach the Gulf of Mexico. Many "IFs" are still present, so a forecast breakdown is needed.
The first factor that needs to be understood is that winter is taking hold slowly over the Northern Hemisphere. This indicates several factors. There are stronger steering currents that can influence storm tracks in the Caribbean. This also limits named storms from tracking too far north into the Central Gulf of Mexico from the Caribbean. This steering current could also bring stronger wind shear, which means water temperatures are not as warm as during peak seasons.
Overall, the North American weather pattern has been very active lately, with a series of high and low pressure systems moving frequently across the U.S. This continued pattern will influence potential Sara.
Currently, a trough of low pressure is working its way across the Central Plains, which is why it has been raining today over much of the Central Plains. As this trough departs, it will leave in its wake a high pressure that will keep any tropical trouble down south in the western Caribbean. Depending on how intense this high pressure is and how fast this next area of tropical trouble develops, it will significantly impact the future track. If the tropical system tracks closer to Central America overall, the land interaction will keep it weaker or even dissipate; if it stays away from land, it will be stronger.
Yet another trough of low pressure will move into the West Coast of the U.S. on Friday this week. It will then widen, deepen, and intensify over the Central Plains early next week, significantly influencing the future track of potential Sara.

The questions at this point before any U.S. insurance impacts can be talked about are:
- How much influence will the current U.S. trough of low pressure and building high pressure behind it lift potential Sara north, or will the tropical system drift so far west over the weekend that it weakens over Nicaragua, Honduras, and Mexico and despite or what intensity and structure of the storm will the storm be in?
- Will the tropical system, as it develops, suffer from an environment that keeps it from getting too strong, like dry air or shear?
- All of this will influence where potential Sara ultimately tracks early next week. Once this occurs it will depend on how fast Sara is moving and its overall structure.
- Potential Sara might not make it out of the coastline of Honduras and there might not be anything to worry about.
What to possibly expect
If you are a model watcher, note that the ECMWF model, which has much better skill than the American GFS model, was recently upgraded on Tuesday. This upgrade represents the latest cycle of science upgrades and improvements to the ECMWF. Based on the ECMWF, it would appear that Sara develops just off the coastline of Honduras. It stalls there over the weekend before Monday, moving towards the coastline of the Yucatan peninsula, where it will likely make landfall as a hurricane, which could be major. By Tuesday next week, the strong trough of low pressure over the U.S. will lift potential Sara north and east. Upper-level dynamics could support intensification as a fast-moving storm as it makes landfall along the west coast of Florida as a hurricane. All in all, think of a similar track to Wilma's in late October 2005. However, at this stage, it is best to use the ensemble forecast to get an idea of the range of possible outcomes which are shown below.


At this time, we will refrain from discussing insurance impacts on Florida, but more Tropical Updates will likely be needed to examine such impacts.
Other Weather Trouble Unfolding:
Keep in mind that while all eyes will be on Sara next week, a blizzard across the upper Midwest is also expected to occur between November 20th and 22nd. Also, keep an eye on the potential for a return to severe weather this weekend into early next week across the southern US. This deep, intensifying trough of low pressure will bring unstable Gulf moisture north as it interacts with arctic air. Lastly, as their series of weather systems move across the U.S. and given the drought conditions across much of the East Coast, there is a heightened wildfire risk across the region as near-record high fire danger will be forecasted due to dry, windy conditions.
