The Atlantic Basin is heating up as the NHC is assessing 3 tropical disturbances with the potential to organize into tropical systems. While the first disturbance, currently named Potential Tropical Cyclone 2 (PTC 2), is forecasted to stay in the southern Caribbean Sea, the other two disturbances have the potential to develop close to the US and its Caribbean territories.
However, though it is very likely we see the next name, Bonnie, adopted by PTC 2, the other two disturbances currently on the National Hurricane Center’s outlook have severely less potential to develop in the next 2 days and even the next 5 days.
Because both tropical disturbances will have to fight off shear and dry air, the National Hurricane Center is not confident that they will develop. In addition, disturbance 1 is running out of runway as it approaches the coastline of the western Gulf of Mexico. Land interactions are also on the horizon for the second disturbance since, if it does develop, it is forecasted to form north of PTC 2 and interact with the Lesser Antilles and other mountainous islands. However, if there is one thing going for all three systems, it is the unseasonably warm sea surface temperatures (SSTs).
Potential Tropical Cyclone 2:
The disturbance recently named PTC 2 earned its name after the NHC deemed that it was close enough to the southern Caribbean islands and South America to issue watches and warnings for the region. Additionally, local convection in the region indicates that the system is trying to organize. Should it close its center of circulation, it will be named Bonnie.
Once the low pressure finally closes, convection will increase as the storm continues to strengthen through a positive feedback loop involving latent heat energy release. As the storm progresses westward, it may make several land interactions before it finally enters the open Caribbean waters ahead of a Central American landfall. Because of the Bermuda High pressure system dominantly controlling the western Atlantic, PTC 2 has been forced to stay off the coast of South America, inhibiting it from thriving off of the warm SSTs to its north.
As for other possible inhibiting factors, PTC 2 is exiting a moderate shear environment and entering a more favorable environment for structural development. Additionally, the system is racing away from the heaviest sections of the Saharan Air Layer (SAL), so convection is also expected to intensify as moisture envelops the system.
Disturbance 1:
Disturbance 1, located in the Gulf of Mexico off the coast of Louisiana has a minimal chance of developing over the next five days (20%). The low probability of development is due to its vicinity to land and the harsh surrounding environment. Not only does it have a short timeframe in which it can form but also it is fighting off shear to its north that is tearing away convection as well as dry air to its south that is limiting the intensity of any developing convection.
Because the disturbance continues to drift southward, interests in the US can begin to relax since any development that could happen would result in the system making landfall in Mexico.
Disturbance 2:
Disturbance 2, which is located behind PTC 2, has been given a minimal chance at development over the next five days (20%) due to its predicted track. In the coming days, the Bermuda High is forecasted to weaken and shift northeastward, providing disturbance 2 with an opportunity to push northwestward. This environment is more hostile than the atmospheric conditions ahead of PTC 2. Disturbance 2 will enter a high shear environment that is also full of the SAL.
