Forecasters estimate a 70 percent chance that the current disturbance between South America and Africa will intensify into a tropical depression or storm. Weather models favor its long-term prospects, and some suggest it could strengthen into a hurricane as it slides slowly west toward the Caribbean.
Another system located in the western Caribbean will bring wet and unsettled weather to Mexico’s Yucatan Peninsula over the weekend.
It’s still early in the 2024 Atlantic hurricane season, which historically doesn’t peak until mid-September on average. Forecasters worry that anomalous warm water temperatures, along with loose high-altitude air generated from a developing La Niña pattern, will favor an exceptionally active season.
Here’s what to know about the system that could intensify this weekend
The more notable of the two systems is now several hundred miles southwest of the Cape Verde Islands in the Atlantic between French Guiana in South America and Sierra Leone in Africa.
The Hurricane Center puts the probability of its development at 70 percent and writes that “a tropical depression or tropical storm is likely to develop several hundred miles east of the Windward Islands this weekend.” The system is moving west at 15 to 20 mph.
In infrared satellites, thunderstorms can be seen and bloom. Already, a dispersal gauge, or sensor on a wind speed satellite, suggested the storm was packing winds of 35 mph. It is below tropical storm strength. It doesn’t have a center yet, so it’s not in danger of becoming a named storm today.
Weather models indicate a gradual, but steady, build-up and intensity of the system over the next few days. There are two factors that reduce its expected reinforcement:
- Sahara Desert (SAL), Or dust trapped in a layer of warm, dry air a mile above the ground. That layer traps warm, moist air below, preventing pockets of air from rising vertically to form thunderstorms. Invest 95L is just south of the Saharan air layer, but SAL can pump the brakes on a faster system.
- cut, Or wind changes with altitude. Scissors across the Mid-Atlantic are a barrier to storms this time of year in the MDR, or Main Development, region of the Atlantic. (This is the imaginary box across the central tropical Atlantic in which many long-track hurricanes form). Shear appears to relax in the coming days, but models often underestimate how much shear there is in the Mid-Atlantic. Following that, Invest 95L may not strengthen seriously until it approaches the Windward Islands late Sunday.
However, once it reaches the Lesser Antilles, it will strengthen into a hurricane. That’s when things become more favorable for a storm to strengthen — and anything in the Caribbean will eventually see landfall.
A second setting to look at
Rain and thunderstorms occurred in the western Caribbean east of Nicaragua and Honduras. Convection, or rain and thunderstorm activity, was intense. That is, not found in circulation.
A belt of strong mid-level winds currently hovering over the Caribbean will hamper its chances of organizing. Paradoxically, tropical disturbances require near-quiet air at many levels of the atmosphere to coordinate. Too much wind chases away any new disturbance, which spells its early demise.
The National Hurricane Center has designated the disturbance a “Leverage 94L” and estimates it has a 30 percent chance of eventually maturing.
It will probably pass near Cancun on Saturday and the Bay of Campeche on Sunday. After that, it breaks down quickly.
