Let me start out by saying this is a “storm” that would never had been named a few decades ago. Here’s the summary from Wikipedia: “On May 17, the National Hurricane Center (NHC) began forecasting the formation of an area of low pressure south of Bermuda, which had the potential to later develop into a tropical or subtropical cyclone. On the following day, a large and elongated area of clouds and thunderstorms developed well to the east of the Bahamas. The disturbance gradually organized over the next two days as it moved westward and then northward, though it still lacked a well-defined circulation.
However, an Air Force Reconnaissance flight late on May 20 revealed that the storm had a well-defined center, leading to the classification of the system as Subtropical Storm Andrea at 22:30 UTC that day, due to being involved with an upper-level low to its west. Soon afterward, Andrea reached its peak intensity. The nascent storm did not last very long (less than 24 hours), as the storm encountered hostile conditions; convection soon dissipated, causing Andrea to become a post-tropical remnant low a day later.”
So…it’s a SUB–tropical storm…for less than 24 hours far out into the ocean. But, it was given a name and…they can claim that we got a “storm” before the official start of the hurricane season for the 5th year in a row.
This is the ACE Index, 1950-2018 from NOAA (link here). The ACE index is a measure of the number and strength of tropical storms. This graph is the North Atlantic Ocean. You can see the top year was 2005 when we had Katrina, Rita and Wilma. You can also see that the graph shows a steady red line…virtually no change in the last 70 years. You can follow the ACE Index through the hurricane season here (Colorado State). You can follow the global ACE Index here.