On Monday afternoon, a low pressure system south of Bermuda was upgraded to Subtropical Storm Andrea, the first of the 2019 hurricane season, and eleven days before the official beginning of the season.
This makes 2019 the fifth consecutive year that a named storm has formed before the official start of Atlantic hurricane season on June 1.
Andrea was fizzling out Tuesday, far from any shore. The National Hurricane Center said people in Bermuda should monitor the storm’s progress, but it said “Andrea is expected to degenerate into a remnant low” pressure system without posing a hazard to land.
Andrea, which formed on May 20, became the sixth preseason storm to develop in the last 10 years. The others were: Alberto 2012 (May 19), Beryl 2012 (May 25), Ana 2015 (May 8), Bonnie 2016 (May 28), Arlene 2017 (April 20), and Alberto 2018 (May 26).
This list omits Alex which formed on Jan. 16, 2016. While it may be technically part of the 2016 season, it was meteorologically a remnant of the 2015 season.
There is clearly a trend toward earlier instances of first storm formation over the past five decades. The median date over this period is June 20, with a range spanning from April 20 to Aug. 30.
There’s nothing magical about the official June 1 start of hurricane season. The start and end dates of the official hurricane season were never intended to contain all of the activity, just the vast majority of it.
When an official “hurricane season” was first defined about 85 years ago, it spanned June 15 to Oct. 31, then it was adjusted to June 15 through Nov. 15, then June 1 through Nov. 15, and finally to June 1 through Nov. 30 in 1965 where it has remained. It could certainly be adjusted again.
Andrea was named a subtropical storm rather than a tropical storm, but in terms of impacts experienced on the ground, there’s not much difference. It’s a technical distinction determined by the structure of the storm and where it is born. A subtropical storm is essentially a mix of a tropical storm — which forms at low latitudes — and an extratropical storm — which forms at high latitudes.
The National Hurricane Center has been tracking subtropical cyclones for many decades, but began assigning names to them in 2002, and all historical statistics have since been revised to incorporate them.
The Associated Press contributed to this report.