Letter to the Editor

A few quiet years can lull individuals into complacency

Wednesday, January 9, 2008

To the Editor:

Accurate long-range predictions of the intensity of upcoming hurricane seasons has eluded forecasters for many decades. Hurricanes, by their very nature, are raw chaos unfolding. What will the next hurricane season bring?

In 2006, a relationship between major Atlantic hurricanes and major U.S. tornados was studied. A strong natural short-term cycle was observed overlaying the long-term multi-decadal cycle of hurricane activity. This research was presented in a paper titled "The Art of Forecasting Extreme Weather Events" at the Second International Conference on Global Warming and the Next Ice Age sponsored by Los Alamos National Laboratory in July 2006.

From this research, a forecasting tool was developed called the storminess model.

A forecasting tool is only as good as its ability to generate accurate predictions. The best way to test the tool's accuracy is to generate a forecast. The storminess model was used to forecast a mild 2006 hurricane season.

"Storminess levels will fall very dramatically from 2004 and 2005 levels. The year 2006 will not produce an extreme in either the number of major Atlantic hurricanes (Category 3 or greater) or in the number of major U.S. tornados (F4 or F5). I predict 0-2 major Atlantic hurricanes for 2006". [CCNet 99/06]

At that time, other forecasters were predicting an intense hurricane season for 2006; whereas the above analysis showed quite the opposite. So this was a good initial test for the tool. The Colorado State University team of Phil Klotzbach and William Gray had generated a Seasonal Hurricane Forecast that predicted five major Atlantic hurricanes for 2006. The National Oceanic and Atmospheric Administration (NOAA) predicted 4-6 major Atlantic hurricanes. Tropical Storm Risk (TSR) with climate experts from the Benfield Hazard Research Centre "warned that the United States and Caribbean should brace themselves for yet another active Atlantic hurricane season in 2006."

Their forecast predicted hurricane activity 60 percent above the 1950-2005 norms. At the far extreme were the computer climate modelers. Although this group does not technically generate forecasts, they began making model predictions that to the layman might be interpreted as forecasts.

Kevin Trenberth from the National Center for Atmospheric Research (NCAR) predicted that human-induced climate change was producing a shift in hurricane intensities toward extreme hurricanes. Kerry Emanuel, a climatologist at the Massachusetts Institute of Technology, suggested that because hurricane intensity was increasing, the Saffir-Simpson hurricane scale should be expanded to include a new category called Category 6 hurricanes.

The year 2006 produced only two major Atlantic hurricanes and the second lowest number of major U.S. tornados since 1950; validating the storminess model. The model was used to analyze the 2008 hurricane season. This time the model predicts a very intense hurricane year. It is very likely (80% probability) that 2008 will be an extreme weather year producing a minimum of five major Atlantic hurricanes. It may be the very nature of this short-term cycle that catches individuals and communities off guard.

A few quiet years can lull individuals into complacency and then the hammer comes down.

James A. Marusek