Subtropical Storm Andrea, the first named storm of 2019, has kicked off the Atlantic Hurricane Season early. Its arrival marks the fifth year in a row to produce a pre-season storm.
Forming south of Bermuda on Monday, it generated winds measured up to 40mph. However, did not last long. It dissipated quickly as it moved north into cooler conditions.
Classified as subtropical, Andrea was a hybrid between a tropical storm and a regular low-pressure system usually found at higher latitudes. A tropical system is fueled by the latent heat released by the evaporation of ocean water while a regular storm is powered by the temperature contrast between air masses. Hybrids are able to access both energy sources.
Hurricane season in the Atlantic is officially designated as June 1 to November 30, but there is nothing inherently magical about those dates. While conditions for storm development are traditionally more likely during that time, storms can form anytime when given the right environment.
Other recent out-of-season storms include: Alberto and Beryl in 2012, Ana in 2015, Alex and Bonnie is 2016, Arlene in 2017, and Alberto in 2018. It is worth nothing that Alex formed in January 2016, but was really more of a late remnant of the 2015 hurricane season.