The 2009 hurricane season is off to a slow start, much to the dismay of Jim Cantore, I’m sure. The real height of the Atlantic hurricane season (which is the only one U.S. Americans care about) is mid-August through mid-October. So, this is no time to panic and start declaring this “The Year without a Hurricane.” Still, even the last three seasons (which have been relatively calm since the monster season of 2005) had at least two named storms by this date in their season. So, how unusual is this occurrence?
The (likely) nice and relaxed folks at the Caribbean Hurricane Network did a little research on the first storms of different seasons. They found 50% of the years had a storm named by July; 75% had a storm named by August 6. (They split their research between Atlantic and Caribbean storms, but the Atlantic almost always has the first named storm.)
So, if we were to go another week or so without a named storm, we might be entering the “unusual” territory. Still, 25% of the years did not see a named storm until after August 6, so it’s not unheard of. If you’re keeping score at home, the latest date for the first named storm in the Atlantic is September 15; October 24 in the Caribbean.
At present, the National Hurricane Center (NHC) is not following any tropical depressions, nor do they expect any development over the next 48 hours.
Of course, a late start to the hurricane season does not necessarily lead to a below-normal season. Our aforementioned Caribbean friends looked at that and found no significant correlation between late starts and a lower number of tropical cyclones. Also, from a public perception standpoint, it only takes one hurricane to make a season seem bad. In 1992, Hurricane Andrew devasted the Florida and Louisiana coasts. To this day, it’s one of the most costliest hurricanes to impact the U.S. and one of only three category five hurricanes to make landfall with such strength. After Andrew formed on August 16, only six more storms formed in the Atlantic and Caribbean that season, with only one making landfall on the continental U.S. (Tropical Storm Danielle). Regardless, no one in southern Florida would consider the 1992 hurricane season “quiet.”
It will be interesting to see how this season plays out… once it gets going, of course.
UPDATE: Watts Up With That? posted today about the quiet hurricane season and included this graph from Ryan Maue’s tropical cyclone page at Florida State:
You’ll notice the current year is set to become the weakest season on the chart (since 1970). As mentioned before, this doesn’t mean the season overall will be weak, but it’s tough to imagine seeing a very active season given the quiet start.