Since Tropical Storm Alberto formed over the weekend, I have received a few phone calls and emails asking how a storm before the hurricane season starts could impact the entirety of the season. Well, I did a little research and discovered some interesting details.
Since hurricane and tropical storm record keeping began back in 1851, there have been 23 seasons that have had storms before June 1.
Two of those seasons, 1908 and 1887, had two storms form before the season began.
Interestingly the chance of a pre-season storm is about the same as finding a season with a category 5 hurricane as there have been 27 seasons with a Cat-5.
Every month has been represented in preseason storms.
In 1978, there was a sub tropical storm in January. 1952 had a tropical storm in February. 1908 saw the first storm of the season in March and it was a hurricane. 2003 and 1992 had systems form in April. Yes, that is correct, I said 1992. In 1992, a sub tropical storm formed in April. Sub tropical storms didn't start getting names until the mid 2000s. So, if today's rules applied, Andrew would have been Bonnie.
Of the 23 seasons with a pre-season storm, 5 had "hyperactive" season with more than 150% of normal activity; 10 had seasons with below normal activity and the rest were within one named storm of normal.
After calculating the averages......seasons with a preseason storm ended up with a season total of 10.7 named storms with 6 hurricanes. That is just about perfectly average for any given hurricane season.
So, the conclusion is simply this....the existence of a preseason storm has no bearing on the totals for the whole season, but the research brought to light some interesting findings.