According to reports, An extremely rare subtropical storm could develop in the Atlantic Ocean this week. Why is this rare? Because according to sources it is a storm that has only occurred once before in March since the pre-Civil War era. This particular storm system is connected with an area of low pressure that has developed well north of the Dominican Republic and Haiti, which has been dubbed Invest 90-L by the National Hurricane Center (NHC).

Excerpt From The Weather Channel:
This naming convention is used by the NHC to identify features they are monitoring for potential future development into a depression or storm. The system brought locally heavy rainfall to Puerto Rico during the weekend, along with rip currents and high surf. Conditions should improve there as the low moves away. If the right ingredients come together this week, a subtropical depression or storm could form from the aforementioned area of low pressure.