Storm & Security

SEASONAL/FORECAST the total seasonal probability of landfall can be forecast with statistical skill. With landfall a function of varying climate conditions, the probability of landfall can be developed through statistical analyses of all U.S. hurricane and named storm landfall events during the 20th century (1900 to 1999). Long-term statistics show that, on average, the more active the overall Atlantic basin hurricane season is, the greater the probability of U.S. hurricane landfall, CSU states. "We anticipate an above-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean," writes Klotzbach. Here are CSU's probabilities of a 2013 U.S. landfall (figures in parenthesis represent averages for the last century): • Entire U.S. coastline: 72 percent (52 percent) • U.S. East Coast including Florida peninsula: 48 percent (31 percent) • Gulf Coast from Florida peninsula to Brownsville, TX: 47 percent (30 percent) The CSU team adds there is a 61 percent probability for at least one major hurricane tracking into the Caribbean. The average for the last century is 42 percent. 12 STORM & SECuRITY PROTECTION / FORECAST 2013 continued AccuWeather.com reports the East Coast to the Gulf of Mexico is at most risk for landfall this season. The Weather Research Center (WRC), Houston, TX, believes there is "a high chance" that three or more tropical storms or hurricanes will make landfall somewhere along the U.S. coast. According to WRC meteorologist Jill Hasling, the Gulf Coast has a 70 percent chance of experiencing the landfall of a tropical storm or hurricane this year. The coast from Georgia to North Carolina has the second highest risk with a 60 percent chance. WRC uses a model called Orbital Cyclone Strike Index (OCSI), which uses the solar cycle (an indication of the solar system's orbit) to predict the risk for coastal residents each hurricane season. The OCSI model is based on the premise that there are orbital influences reflected in the global circulation pattern on the sun as well as the global circulation pattern on Earth. WRC also foresees a high probability for a long hurricane season this year. While indications were low (22 percent) of a cyclone developing as early as May this year, there is a higher probability (55 percent) of a tropical cyclone as late as November.

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