Possible subtropical storm later this week
In the central Atlantic, there is a low-pressure trough that may be developing a subtropical storm. In fact, many models are predicting that a subtropical storm would develop in the central Atlantic by late tomorrow or early Tuesday. The models are depicting that a storm cuts off from a trough. The system would then move slowly westward and persist just to the east of Bermuda over several days before moving north-northeastward and being absorbed by another low-pressure trough over east Canada on late Friday or early Saturday. I doubt that the system would become a tropical storm as the area is not favorable for a tropical cyclone to form, but rather subtropical in nature. Residents of Bermuda should monitor closely on the developing system as it would be close to this area on Wednesday. If the subtropical storm develops, then this will be third subtropical storm on record in the Atlantic basin during the month of April. I give the formation of a subtropical storm a 60% chance to occur.
Figure 1. Track of Tropical Storm Ana in 2003.
Other April subtropical storms
In 1992, Subtropical Storm One was developed over the central Atlantic on April 21 and then dissipated on April 24. In 2003, Tropical Storm Ana was separated from a frontal system and developed into a subtropical storm on April 20. It became a tropical storm on April 21 and then dissipated on April 24. Ana remains the only tropical cyclone to form over the Atlantic in the month of April.