This season will have the potential to be rather active in the Gulf Coast, western Caribbean, western Atlantic, and East coast in terms of potential tropical disturbances but likely not in terms of major hurricanes unlike the previous years.
The key factors for the Atlantic Hurricane Season will be the increasingly active MJO with dominant phases in 7 through 2 and the cool state of the majority of the tropical Atlantic. There will be talk about developing ENSO influence in the form of an El Nino, but thus far all data points to any El Nino development won’t get started until late in the Fall, thus majority of the season will be unaffected by ENSO influences.
I see the Gulf of Mexico, western Caribbean, western Atlantic, and East coast to be active in terms of potential shortwaves. The MJO influences will keep convection developing in these areas via an active Inter Tropical Convergence Zone (ITCZ) in the Caribbean and stalled frontal boundaries in the Gulf Coast and western Atlantic.
The MJO phases 2 through 7 will generally keep a mean trough axis between the Mississippi River Valley and Ohio River Valley, which will allow a western Atlantic ridge to be established . This western Atlantic Ridge will be enhanced by the above normal Sea Surface Temperature Anomalies (SSTA) over the western Atlantic, which is a hall mark of a negative AMO state that is developing.
Given these factors above, there is likely going to be plenty of weak tropical disturbances, now called PTC, and Tropical Depressions focused in these areas. Tropical Storms likely will have a shot to develop in the warm western Atlantic and this area between the Bahamas, East coast of the United States, and Bermuda; is likely where most of the hurricanes will develop and intensify as well. The good news is a pattern like this more often than not will keep tropical low pressure systems either off the East coast or weak due to strong southwesterly wind shear leading to just heavy rainfall events.
The rest of the Tropical Atlantic will be influenced by growing cold SSTA from the African coast to the central Caribbean. While atmospheric conditions will be favorable for tropical development, the cold SSTA that are expected to intensify as the Summer continues, will significantly limit tropical low pressure develop. This state of the AMO heading to a negative phase has been shown to limit the rate of intensification of tropical low pressure systems.
With the Atlantic growing even colder, forecast was reduced on June 1 to the following:
NORMAL: 12 storms 6.5 hurricanes 2 major ACE: 92
FORECAST: 16 storms 7 hurricanes 2 major ACE: 100
JUNE UPDATED FORECAST: 16 storms 4 hurricanes 2 major ACE: 80