Active hurricane season predicted: Film at 11

Stop me if you've heard this one before.

Like most other forecasters who have, or will soon, released their predictions, [hurricane season prognosticator Bill] Gray sees an active year, meaning the Atlantic should see more storms than usual. Gray said today he expects 15 named storms this year. But what does this really tell us?

Not much, as it turns out.

Seasonal forecasters suggest people shouldn't obsess on the specific number of storms predicted. Instead, forecasters, including Gray, say it's important to focus on the predictions for which they say there is some skill, namely whether a hurricane season will have above- or below-normal activity.

Gray defines normal activity as the average number of named storms that occurred between 1950 and 2000. The average during that period was 9.6 named storms -- that is, tropical systems that achieved at least tropical storm status and were designated by the National Hurricane Center as Allison, Bret, Charley and so forth.

Hurricane forecasters generally agree the Atlantic entered an active period in 1995, when some driver -- be it natural forces, global warming or some combination thereof -- began warming sea surface temperatures in the tropics and causing more storms to form.

Since 1995, only two years have been below the 9.6 average: 1997 (seven) and 2006 (nine). By those odds, as scientists say we're still in a warm Atlantic period, one probably can expect there's an 85 percent chance Gray will be right with his prediction that this will be an active year.

It's kind of like predicting the Red Sox and Yankees to compete for the American League East, isn't it? But as the article goes on to suggest, these preseason predictions are often just rough guesses.

Predicting the actual number of storms in a given year, especially five months before hurricane season peaks, is even more problematic, as recent seasons have suggested.

Before the hyperactive 2005 season, for example, Gray forecast 13 named storms in April. There were 26.

And for the 2006 season, perhaps in reaction to the active 2005 season, he predicted 17 named storms in April. There were nine.

The National Oceanic and Atmospheric Administration also has faced criticism as it has trumpeted its own seasonal forecast in recent years, releasing it to much media fanfare during nationally broadcast news conferences. But NOAA's forecasts have been as wrong as Gray's.

So, at this year's National Hurricane Conference, the new director of the National Hurricane Center, Bill Read, said NOAA would seek "a lot less publicity" for the 2008 seasonal forecast to be released in mid-May.

SciGuy, who wrote the article, has more. Basically, consider these early forecasts to be more suggestion than command, and pay closer attention to the revised forecasts later in the year.

Posted by Charles Kuffner on April 11, 2008 to Hurricane Katrina