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May 23, 2009

Hurricane Video  

Short video on the destruction a hurricane can do.

2009 HURRICANE SEASON  


Many of you are familiar with the Atlantic seasonal forecasts of named storms and hurricanes. At The Weather Channel we do NOT make seasonal forecast, instead we have tried to provide the message that it only takes one to hit your area so be well-prepared every hurricane season regardless of these forecasts. But each late winter/spring leading up to the June 1st start of hurricane season it happens, first whispers of the season outlook that turn into talking about them and finally preoccupation with them. Often there is a slant toward how terrible hurricane season is going to be; more rarely how mild it will be. Just remember it will be a very bad and memorable hurricane season, even if there is a total of only one Atlantic hurricane, if that one strikes your area! Below I attempt to give a perspective on the early forecasts for 2009 and how one might interpret them. Keep in mind that there is some sound (although highly volatile) science involved in making some of these forecasts, in others I am uncertain how the numbers are arrived at. In any event, this is not an attempt to demean these forecasts or the people or companies that make them. Instead it is written for you and how you might react/respond to them.
OK, we first have to examine some of the 2009 forecasts that have been put out there thus far; so I list some of them you may find in the news or on the web. I am sure you can find additional forecasts, but I will focus on these for simplicity.
# Named# Hurricanes# Major Hurricanes
Colorado State/Bill Gray1473
NOAA/National Weather Service******
Weather Services Inc.1373
Accuweather1382
Wx Research Center74-
** Not yet released.
As a reference frame for you to relate to these forecasts, I show below a long-term approximately 50 year, the average since the Atlantic "active era" began in 1995, and the active era minus 2005. Keep in mind that the huge 2005 hurricane season was extremely anomalous with 27 named storms, so I also show the active era average excluding this very anomalous year.
# Named# Hurricanes# Major Hurricanes
Long term average1162/3
Average 1995-20081584
Average 1995-2008 (minus 2005)1373/4
Now it becomes clear that three of four 2009 hurricane season forecasts currently available are close to a climatological forecast of "average" relative to the past 14 years minus 2005. The Weather Research Center forecast is only about 60% of that average. Their forecasts have seemed to consistently be lower than most other forecasts, but because of that they did better than others in 2006! One interesting thing is that within the 14-year period since 1995, the actual number of named storms has routinely departed from average with a low of 9 named storms in 2006 to a high of 27 name storms in 2005 (19 in 1995); so there are very large year-to-year variations in the number of Atlantic Basin named storms.
Note that all of these forecasts are for the entire Atlantic Basin and do not necessarily have anything directly to do with how many might strike the U.S. coastline. It turns out that within the recent active era (1995-2008), the relationship between the number of Atlantic storms that formed and the number that struck the U.S. was poor; for example, only about 15% of U.S. storm and hurricane landfall variations are explained by knowing "exactly" how many storms and hurricanes formed in the Atlantic Basin after the season ended (this assumes a perfect seasonal forecast)! More importantly, Atlantic Basin forecasts say nothing about how strong or where a storm or hurricane might strike. Wording within some of these seasonal forecasts provides general information about U.S. strikes and/or strike probabilities, but verification of them in a scientific manner would take years of forecasts and verifications to identify any meaningful skill of being correct compared to chance/guessing. Of course someone "could" take an approach of forecasting landfall in a specific area over and over again year after year, and just by basic climatological probabilities of where storms/hurricanes hit the U.S. coast, eventually they will be successful in one year, but they will have provided many forecasts of false alarm to the public, there is "no skill" in this approach.
So where does this leave us? IF I could tell you with 100% certainty a hurricane will strike your coast on September 10, 2009, would you do anything between now and then? Obviously no one can make such a forecast with any skill. So you should be ready, ready just as well every year for a potential hurricane strike. Eventually one will come to your coast, it could be in 2009 or it may be 100 years from now, but the potential for great disaster requires you to be ready just like when you put on your car seatbelt each time you start your car, never expecting to get in a crash. Be readyto put on those house shutters and get out your pre-prepared hurricane plan of action. Then you can sit back like I do and muse at how each seasonal forecaster and each media outlet feeds you these curious, but relatively inapplicable long-range forecasts.