Ana, Alex, Bonnie, Arlene, Alberto, Andrea, and Arthur…
Tropical Storm Arthur, the first storm of the 2020 season, became the seventh storm in the last six years to form prior to the start of hurricane season on June 1st. In fact, since 2000, 13 storms have formed in April or May. Early season storms are nothing new, as 52 storms have formed in the month of May in recorded history. This number accounts for more than half of the number of storms to form outside of hurricane season. Storms that form this early usually develop in similar locations to June systems – in the Western Caribbean, Gulf of Mexico, or Southwest Atlantic near the Bahamas.
Early season storms do not translate to a more active year. Since 2000, 10 seasons (omitting this one) have featured a storm prior to the season beginning with an average number of storms in those years of 15.1. In the same span, the average number of storms per season is 15.3, although that number is skewed slightly by the record breaking 2005 season. With these numbers, years with an early storm have seen above normal activity six times, normal activity two times, and below normal activity two times.
This season is expected to be an above average year for tropical systems, but this early start does not necessarily mean the year will end busy.