Over night Invest, or investigative area, 97L developed into tropical depression 4 and is now expected to become the fourth tropical storm of the 2024 Atlantic hurricane season, with what will be named storm Debby currently organising and heading towards the Gulf of Mexico and then for Florida.
Meteorologists have been watching Invest 97L for a number of days now and forecast model runs are showing a strong chance for it to achieve tropical storm status and be named as Debby.
It became tropical depression 4 last night and is now forecast to become Debby, with a chance seen for it making low category hurricane status by landfall.
The National Hurricane Center (NHC) has said in its latest update, “Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. Strengthening is forecast during the next several days, and the depression is expected to become a tropical storm later today and continue strengthening over the eastern Gulf of Mexico through the weekend.”
Currently, the depression is tracking along the south of Cuba, with convection said to be becoming increasingly robust and forecast models trending towards a more westerly track that will take a tropical storm Debby over the straits of Florida and into the Gulf of Mexico.
Forecasters say conditions are set to become more conducive for development as tropical depression 4 moves on its north-westerly track, with most models now opting for it to head deeper into the Gulf and then curve towards the Florida Big Bend area of the Panhandle at this time.
The image below from Tomer Burg’s excellent weather resources shows the forecast path and cone of uncertainty, as well as wind intensity forecasts:
The forecast now predicts tropical storm Debby will reach sustained winds of around 70 mph before landfall as it passes over very warm Gulf waters, with a hurricane Debby landfall seen as possible.
The model intensity guidance from TropicalTidbits.com (below) shows most opting for a relatively strong tropical storm Debby, but only a few for Debby to attain hurricane status at this time.
Forecasters are warning that this system could pick up a lot of moisture as it moves towards Florida and the south eastern United States, with some cautioning that flooding could be a concern no matter how strong the winds from tropical storm Debby become.
Meteorologists say the steering flow that directs the depression is going to be critical, as a track further into the Gulf of Mexico could give the storm more time to strengthen before curving back towards the west coast of Florida or the Panhandle.
The forecast also calls for Debby to sustain tropical storm wind speeds and emerge off the east coast of Florida where it could intensify again before heading up the coast of the Carolinas.
Some models show a second landfall is possible around North Carolina, where tropical storm Debby could again be nearing hurricane status and the rainfall threat is expected to remain significant as well, with more time off the coast to pick up additional moisture.
So a lot of uncertainty still and hence something for the insurance, reinsurance, catastrophe bond and insurance-linked securities (ILS) markets to track this weekend.
Catastrophe bond fund manager Icosa Investments AG commented on the potential for storm Debby development on Friday, saying it is tracking the system closely, as other cat bond and ILS fund managers will be.
Icosa Investments said, “While forecasts vary regarding its path, the general consensus is that the system will approach Florida from the western coast (possibly near Tampa), cross the Floridian peninsula, and then move back into the Atlantic before moving Northeast.
“Most intensity forecasts do not anticipate for the system to reach hurricane strength. However, given the warm sea surface temperatures and low wind shear, there’s still a small possibility that models underestimate the potential for intensification, similar to what occurred with Hurricane Beryl recently. Fortunately, the system’s current lack of organisation limits the time available for significant strengthening before it makes landfall.
“At this point, we do not expect any impact on cat bond investors, even though a Category 1 hurricane could still cause billions of insured losses if it directly hits the densely populated Tampa area. Such an event might result in some attachment erosion, but is unlikely to result in significant outright losses in the cat bond market. There is also some uncertainty regarding the storm’s path after it reemerges into the Atlantic, with potential impacts in North Carolina — a region well-represented in the cat bond market — still possible.”
