What does May have to say about hurricane season?
Bottom Line: It's probably not a surprise that of the six offseason months – May is by far the most active. With Alberto making landfall on Memorial Day coming off of an active season last year the inclination is to worry about what lies ahead this year. Of course, we won't really know until we get there but history can be a guide. I decided to take a look at May's tropical storm and hurricane history to see what history suggests.
Here's a quick rundown. Since official record keeping of the Atlantic hurricane season May has accounted for...
49% of all offseason Tropical storms & 33% of all off season hurricanes
Looking back to 1950 we've had 13 named storms in the Atlantic in May (not counting Alberto this year). That means we average a tropical storm or hurricane in May about once every five years. Taking a look at the history of those 13 years here's what we find...
We've averaged 12.4 named storms in the years when we had a named storm in May compared to 11.8 named storms in the years we haven't. So, do May storms predict an above average season? Technically yes, 5% more active than normal, but that's the equivalent of less than one extra system so that's the good news. Plus, the most active season on record, 2005 with 28 named storms, didn't include any named storms prior to the official start of hurricane season.
If you're looking for a silver lining, there it is. Perspective is also important. We tend to judge hurricane seasons based on what impacts us the most rather than overall activity. For example, 1992 ties for the least active hurricane season of the past 30+ years but all it took was Andrew to make it one of the most devastating ever. Conversely 2010 was the second most active since 1933 but it probably doesn't register any or many memories because in Florida we only had to contend with a tropical storm that year. History is on our side if you're looking for it. Since 1950, 2004 and 2005 are the only years that Florida has been hit with a hurricane in back to back years. Somewhat remarkably however Florida was hit with at least one hurricane in four straight years from 1947-1950.